2003 Infiniti QX4 Fuel and Emissions Systems

Essential Fuel and Emissions Systems for 2003 Infiniti QX4s

Carquest – Fuel Pump Lock Ring (Part No.579-019)

Fuel Pump Lock Ring

from

$21.49
Recommended for replacement whenever the sending unit is serviced, this fuel tank sending unit lock ring securely retains the fuel pump assembly to the lock. Made of durable materials for reliable service.

Product Features:
  • Direct replacement – this fuel tank sending unit lock ring is made to match the fit and performance of the original ring on specific vehicle applications
  • Recommended for replacement whenever the sending unit is serviced, this fuel tank sending unit lock ring securely retains the fuel pump assembly to the lock
  • Durable construction – this part is made from quality materials to ensure reliable performance and long service life
  • Trustworthy quality – backed by team of product experts in the United States and more than a century of automotive experience
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Kyosan – Electric Fuel Pump (Part No.E3000159571KYO)

Electric Fuel Pump

from

$286.02
The Kyosan Electric Fuel Pump meets or exceeds the OE specifications for fit, durability and performance.

Product Features:
  • OE-Equivalent electric fuel pump.
  • Direct fit for easy installation.
  • OE connections and fittings.
  • Highly efficient turbine design.
  • Designed for quieter operation.
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NTK – Switching Oxygen Sensor: 4 Wire, 39.5" Long, Heated, Direct Fit (Part No.24574)

Switching Oxygen Sensor: 4 Wire, 39.5" Long, Heated, Direct Fit

from

$112.99
NTK is the world’s largest supplier and manufacturer of OEM oxygen sensors. Oxygen sensors play a critical role as part of the vehicle’s on-board diagnostic system in maintaining optimal engine performance, maximizing fuel efficiency and reducing harmful emissions. Providing constant closed loop feedback to the ECU, oxygen sensors help to control the air-fuel ratio while alerting OBDII systems of possible problems with fuel delivery or catalytic converter efficiency. A ceramics company at our core, NTK uses state-of-the art technology enabling control of the ceramic element used in our oxygen sensors from raw material to finished product. Trust The Sensor Specialist for full-line market support and OE application technology.

Product Features:
  • OEM QUALITY: NTK is the world’s largest supplier of original equipment oxygen sensors with renowned quality that meets or exceeds OEM specifications
  • PRODUCT ENGINEERING: Based on OE expertise, but specifically engineered for the aftermarket, NTK Oxygen Sensors offer superior OE fit, form, function
  • OE TECHNOLOGY: Upgraded to the latest OE technologies, NTK Oxygen Sensors are designed to reduce OE failures, enhance durability and performance
  • EXTENSIVE TESTING: OE development includes vibration and thermal shock testing. Testing during manufacturing guarantees quality and reliability
  • EASY INSTALLATION: NTK Oxygen Sensors are equipped with OE specified, water-resistant connectors and harness accessory hardware for easy installation
  • ADVANCED CERAMIC SENSOR ELEMENT: 3-stage contaminant-resistant plasma jet and deposit trap overcoat protects against element poisoning
  • NTK ADVANTAGE: Superior dual-coated platinum interface and thinner ceramic element produces fastest light off and response times with best durability
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Dorman – Nissan Splash Shield Retainer (Part No.961-031D)

Nissan Splash Shield Retainer

from

$4.49
Constructed of quality materials, this multi-purpose retainer provides the same function and versatility as the original equipment retainer ensuring long service life.

Product Features:
  • Ideal replacement – this retainer matches the fit and function of the original equipment retainer for this vehicle application
  • Quality material – this retainer is made of durable material for long-lasting service
  • Versatile design – this retainer is suitable for a variety of automotive uses
  • Excellent value – this part offers original equipment quality at a competitive cost
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Delphi – Fuel Tank Cleaning Kit (Part No.FC01)

Fuel Tank Cleaning Kit

from

$12.49
When replacing a fuel pump or module, it’s extremely important to clean the tank. Existing dirt, debris, and contamination stuck in the fuel tank can clog the brand-new strainer. Delphi’s Fuel Tank Cleaning Kit (FC01) and Tool (FC02) can help clean your fuel tank in less than five minutes. The FC01 includes a low-suds solution, cloth, and gloves that works together with the FC02 to help clean those hard to reach places without having to remove the fuel tank. Visit our Resource Center for helpful tips and tricks on fuel pumps, technologies, and more: https://www.delphiautoparts.com/usa/en-US/resource-center.

Product Features:
  • Helps avoid premature fuel pump failure
  • Lint free towel included
  • Low suds formulation
  • Removes harmful contaminants from the fuel tank
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Carquest Premium – Exhaust Gas Recirculation (EGR) Vacuum Regulator Solenoid Connector (Part No.PTA2918)

Exhaust Gas Recirculation (EGR) Vacuum Regulator Solenoid Connector

from

$149.99
CARQUEST premium engine management products provide the right products for a wide range of domestic and import applications. Delivering the highest performance and durability under demanding conditions.
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Spectra Premium – Fuel Tank Strap (Part No.ST359)

Fuel Tank Strap

from

$80.99
Innovative engineering, manufacturing technology and quality control ensure that Spectra Premium fuel tank straps meet or exceed the performance of the original equipment they replace.

Product Features:
  • Unit is designed to OE fit, form and function requirements accomplished by leveraging our expertise
  • Direct fit ensures safe, secure fuel tank installation
  • Product individually packaged and labeled to help reduce product damage prior to installation
  • Industry leading coverage on straps for plastic tanks
  • Manufactured with double-layered steel on the mounting brackets for a more robust solution
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Felpro – Fuel Injector O-Ring Kit (Part No.ES 70599)

Fuel Injector O-Ring Kit

from

$7.49
Fel-Pro gaskets offer 100% vehicle sealing with application-specific materials to give you sealing solutions with the performance and durability professionals trust

Product Features:
  • Meets or exceeds all original equipment specifications
  • Application specific design to ensure a perfect fit
  • Engineered for the sealing repair environment
  • Unsurpassed quality you can trust
  • Validated for fit, form, and function
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Dorman – Fuel Sending Unit Retainer Assortment (Part No.E3004418238DOR)

Fuel Sending Unit Retainer Assortment

from

$13.80
Recommended for replacement whenever the sending unit is serviced, Dorman’s Fuel Tank Sending Unit Lock Ring securely retains the fuel pump assembly to the lock. Its heavy-duty steel or plastic construction ensures a long life.

Product Features:
  • Comes with rubber seal or gasket
  • Direct replacement for a proper fit every time
  • Corrosion-resistant
  • Quality-tested for trouble-free performance
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Carquest – Fuel Injector (Part No.63825)

Fuel Injector

from

$112.05
High-quality products that meet OE appearance and performance to provide professional technicians and DIYers with a cost-effective solution.

Product Features:
  • Designed to OE standards for ease of installation
  • Stainless steel calibration slide and spring assembly prevents corrosion within the fuel control body leading to an extended service life
  • Precision wound and trimmed solenoid windings allow the computer to command efficient delivery of fuel
  • High-temp Viton O-rings enable prolonged sealing of injector under extreme heat conditions
  • Fiber optic yttrium aluminum garnet “YAG” laser welding and 100 million cycle testing ensure quality in every box
  • With industry leading expertise, when original equipment fails our products are designed to fix the inherent failure issues
  • BWD is a global manufacturer of original equipment and aftermarket fuel injection products, complete quality control is maintained through the manufacturing process from componentry to finished product
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Carquest Premium – Fuel Injector Connector (Part No.PTA1064)

Fuel Injector Connector

from

$4.29
CARQUEST premium engine management products provide the right products for a wide range of domestic and import applications. Delivering the highest performance and durability under demanding conditions.
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Bosch – Oxygen Sensor (Part No.C501058219BOS)

Oxygen Sensor

from

$78.43
The Bosch oxygen sensor utilizes a mix of zirconium and yttrium oxides and other elements to form a tough base that withstands the intense stress to which oxygen sensors are subjected. Each element is incredibly strong for best-in-class performance and maximum service life.

Product Features:
  • OE-Equivalent.
  • Direct fit for easy installation.
  • OE Style connectors and wire lengths.
  • Base ceramic probe of Zirconium and Yttrium.
  • Patented Platinum Power Grid.
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Hitachi – Air Intake Temperature Sensor – New Actual OE Part (Part No.TMS0003)

Air Intake Temperature Sensor - New Actual OE Part

from

$39.49
Hitachi is a Tier One OE supplier to the largest automobile manufacturers globally, delivery industry leading quality, and exceeding customer expectations with our products and service. Hitachi is bringing that same knowledge and expertise to the premium products we deliver in the Aftermarket because Quality Matters. Hitachi’s line of vehicle sensors are crucial to an efficiently operating vehicle. Whether is it an Automatic Transmission Speed Sensor, Crankshaft Angle Sensor, Camshaft Angle Sensor, Knock Sensor, Pressure Sensor, Temperature Sensor, Throttle Position Sensor, or Oil Level Sensor, you can rely on accurate readings and signals to be transmitted to your vehicles’ Electrical Control Unit (ECU) for an efficiently running system. Hitachi uses premium components and materials in the construction of all sensors extending the service interval of the product. Designed to meet the exact needs of each specific vehicle, Hitachi’s Sensors are the premium choice. Hitachi sensor line supports accurate measurement for reliable engine performance.

Product Features:
  • Hitachi is a Tier 1 OE supplier for temperature sensors
  • 100% NEW, never remanufactured
  • Meets the OE performance and durability standards for this application
  • Accurate and reliable measurements
  • Provides accurate measurement; reliable engine performance.
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Carquest Premium – Vapor Canister Purge Solenoid (Part No.CPC1055)

Vapor Canister Purge Solenoid

from

$87.99
Carquest premium engine management products provide the right products for a wide range of domestic and import applications. Delivering the highest performance and durability under demanding conditions.
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Delphi – Fuel Injection Pressure Regulator (Part No.FP10400)

Fuel Injection Pressure Regulator

from

$82.99
100 years of OE experience, supplier to the world’s top automakers, OE Heritage and knowledge built into every aftermarket part.

Product Features:
  • Precisely manufactured internal valves, diaphragms and springs means excellent performance under all engine operating conditions
  • Quiet operation, no audible regulator noise
  • Robust diaphragm materials means longer life, improved durability and compatibility with a wide range of fuels
  • Consistent and predictable fuel pressure throughout system range of control provides great drivability
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Carquest Premium – Idle Air Control Valve (Part No.AEC1051)

Idle Air Control Valve

from

$149.99
CARQUEST premium engine management products provide the right products for a wide range of domestic and import applications. Delivering the highest performance and durability under demanding conditions.
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Ishino – Fuel Rail Insulator (Part No.C1008251685ISH)

Fuel Rail Insulator

from

$1.85
Fuel Rail Insulator

Elring – Fuel Injector Seal (Part No.C1010681908ELR)

Fuel Injector Seal

from

$2.51
Fuel Injector Seal

Dorman – Evaporative Vacuum Cut Valve (Part No.911-508)

Evaporative Vacuum Cut Valve

from

$121.99
Engineered for a perfect fit and plug-and-play installation, this vapor canister purge valve is a direct replacement for the original equipment purge valve. It is critical to the evaporative emissions system and fulfills government requirements.

Product Features:
  • Direct replacement – this vapor canister purge valve fits and functions like original equipment to ensure proper function of your vehicle’s evaporative emissions system.
  • Quality construction – manufactured from premium materials for a long service life.
  • Excellent value – original equipment quality at a lower price
  • Quality tested – has undergone testing to ensure proper fit and performance
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Carquest Premium – Fuel Cap: 10838, Twist-Lock, Direct Fit, Provides Tight Seal, 1 Pack (Part No.10838)

Fuel Cap: 10838, Twist-Lock, Direct Fit, Provides Tight Seal, 1 Pack

from

$17.79
Manufactured with OEM quality materials and safety standards by an OE Supplier. Manufactured to pass all state and federal emissions requirements. Specifically designed pressure and vacuum relief valves to prevent evaporation of fuel. A leaking fuel cap can allow up to 30 gallons of gasoline to evaporate over the period of a year.

Product Features:
  • Passes all state and federal emissions tests
  • Manufactured from durable, long-life materials
  • Reduces air pollution with proper sealing and venting
  • Independently tested for emission control
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Hitachi – Idle Control Valve (Part No.C4030253557HIT)

Idle Control Valve

from

$242.47
Idle Control Valve

Nippon Reinz – Fuel Inject Cushion Ring (Part No.C101145504NRZ)

Fuel Inject Cushion Ring

from

$5.29
NIPPON REINZ engineers work with OEMs to develop complete engine sealing solutions for gasoline, diesel, and alternative energy vehicles. We employ custom sealing solutions through our expert problem solving utilizing our regional research and development centers. As an Integral Partner with Virtually Every major vehicle and engine manufacturer worldwide, NIPPON REINZ offers a comprehensive range of sealing Innovative Systems, INCLUDING Head gaskets, Heat shields, sealing modules, secondary gaskets, Valve stem Seals, and transmission components.
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Hitachi – Air Flow Sensor – New Actual OE Part (Part No.MAF0024)

Air Flow Sensor - New Actual OE Part

from

$343.99
Hitachis Air Flow Sensors (MAFs) measure the amount and characteristics of air entering the engine. Hitachi uses precision elements and high-quality components for enhanced durability and accurate air flow measurements. Hitachi MAFs are 100% air flow tested for ideal performance and are calibrated for each application ensuring your vehicle meets the strict emission standards set by the manufacturer. Details such as a contaminant bypass port (when applicable) and protected circuitry providing a durable and reliable product approved by OE manufacturers makes Hitachis air flow sensors the premium choice.

Product Features:
  • Hitachi is a Tier 1 OE supplier for air flow sensors
  • 100% NEW, never remanufactured
  • Hitachi’s advanced precision elements and high quality components provide enhanced durability. We feature exact fitment and calibration for each vehicle, which assists engine efficiency and fuel mileage. Our sensors are 100% air flow tested to meet exac
  • Precision manufactured and assembled sensing elements for accurate air flow measurements
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Carquest Premium – Ambient Air Temperature Sensor (Part No.WTA1186)

Ambient Air Temperature Sensor

from

$43.99
CARQUEST premium engine management products provide the right automatic transmission speed sensor for a wide range of domestic and import applications. Delivering the highest performance and durability under demanding conditions. Designed to meet OE quali

Product Features:
  • Lifecycle tested to meet or exceed OE specifications
  • Direct OE replacement
  • High strength thermoplastic is resistant to shock, temperature and chemicals. Also protects internal components from moisture and contaminants.
  • Global coverage for import and/or domestic applications.
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Carquest Premium – Manifold Absolute Pressure Sensor (MAP) (Part No.AEE1033)

Manifold Absolute Pressure Sensor (MAP)

from

$115.99
CARQUEST MAP sensors are manufactured with critical OEM components to ensure that your engine runs efficiently to reach the best gas mileage on your vehicle.

Product Features:
  • CARQUEST MAP sensors connectors are exact OE fit to ensure the proper vacuum is maintained to prevent power loss and to minimize internal contamination.
  • CARQUEST MAP sensors utilize high temperature resistant seals. Damaged seals can directly impact the vehicles fuel-to-air ratio, making it less fuel efficient.
  • CARQUEST MAP sensors are 100% individually tested for all product functionalities including proper vacuum seal and electrical output.
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Spectra Premium – Fuel Pump Strainer (Part No.STR11)

Fuel Pump Strainer

from

$15.49
Innovative engineering, manufacturing technology and quality control ensure that Spectra Premium strainers meet or exceed the performance of the original equipment they replace.

Product Features:
  • Designed with gradient density to meet or exceed OE specifications
  • Engineered and developed in Canada
  • Designed to ensure optimal filtration to prevent fuel system contamination
  • Strainer material tested and validated for capacity and efficiency by accredited, third party
  • Engineered to stringent tolerances based on our Canadian engineers’ in-depth knowledge of the OE part it’s designed to replace
  • Engineered and developed by Spectra Premium; proud member of the A.A.S.A. fuel pump manufacturers working group
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Ishino – Fuel Injector O-Ring (Part No.C101245500ISH)

Fuel Injector O-Ring

from

$1.25
Fuel Injector O-Ring

Carquest Premium – Fuel Cap Tester Adapter (Part No.12410)

Fuel Cap Tester Adapter

from

$15.99
Fuel Cap Tester Adaper for use with Stant fuel cap testers. Color coded for easy identification. Made of durable plastic.

Product Features:
  • BAR Certified adapters
  • Adapter check’s a fuel cap’s ability to hold pressure.
  • Adapters meet EPA standards for recommended fleet coverage.
  • Check adapter application chart for specific makes and models
See More

Upgrade your 2003 Infiniti QX4 with Top-Quality Fuel and Emissions Systems

When it comes to maintaining or upgrading your 2003 Infiniti QX4, nothing is more important than using high-quality OEM or aftermarket parts that you can trust. Whether you’re repairing damage to your Infiniti or enhancing its overall performance, Fuel and Emissions Systems are key to keeping your QX4 functioning at its best. At Advance Auto Parts, we offer a wide selection of 88 Fuel and Emissions Systems for the 2003 Infiniti QX4, designed to meet your needs without breaking the bank. From Fuel Pump replacements to Gas Caps upgrades, we’ve got you covered with parts that fit your vehicle perfectly and ensure long-lasting performance.

Affordable Prices and Wide Selection

Shopping for Fuel and Emissions Systems for any vehicle can be a hassle, especially if you’re on a budget. But with Advance Auto Parts, you can find high-quality Fuel and Emissions Systems for your 2003 Infiniti QX4 at great prices. Our Fuel and Emissions Systems inventory for this model ranges from just $1.85 to $448.99, with an average price of $92.96. Our 88 Fuel and Emissions Systems in stock come from 22 trusted brands, so you’re sure to find the right part for your 2003 Infiniti QX4 without overspending.

Top Brands and High Customer Satisfaction

Advance Auto Parts takes pride in offering only the best brands in the automotive industry. For your 2003 Infiniti QX4, we stock popular OEM and aftermarket Fuel and Emissions Systems from top names like FELPRO Carquest Premium, and more. FELPRO Fuel and Emissions Systems start at just $3.29 and boast an impressive 5 stars average rating from customers. With 459 customer reviews and counting, our 2003 Infiniti QX4 Fuel and Emissions Systems have a strong track record of reliability, ensuring you can trust your purchase.

Explore Related Parts and More

While you’re here, don’t forget to check out other essential categories that go hand in hand with Fuel and Emissions System upgrades. Explore related part types like Batteries and Chargers, Oil and Lubricants and more to make sure your 2003 Infiniti QX4 is always ready to roll. We’re committed to providing you with everything you need to keep your QX4 in top shape, all in one place. Start shopping confidently below for your 2003 Infiniti QX4!

Best-Selling Fuel Pumps for 2003 Infiniti QX4s

Enhance the driving experience in your Infiniti with 6 quality Fuel Pump components, starting at $15.49.

Carquest Premium – Fuel Pump Includes Wiring Harness (Part No.E3510434)

Fuel Pump Includes Wiring Harness

from

$149.99
Carquest Premium electric fuel pumps are engineered by Carter Fuel Systems or Agility Auto Parts to meet or exceed Original Equipment (OE) specifications for fit, form and function. Our Carquest Premium fuel pumps are built to be installed in the Original Equipment module or assembly. We have invested in industry-leading quality upgrades, like upgraded turbine impellers and 100% carbon commutators, to deliver greater reliability. Carquest Premium electric fuel pumps are engineered with superior quality components to provide the longest life and reliable performance.

Product Features:
  • Meets or exceeds OE specifications for fit, form and function
  • 100% carbon commutators provide resistance to aggressive fuels and double the life expectancy of the pump
  • OE upgraded turbine impellers greatly reduce fuel pulsation
  • All fuel pumps are 100% performance tested
  • Includes installation gaskets or seals where applicable
  • Includes fuel pump strainer
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Carquest Premium – Fuel Pump Strainer FS2321774 (Part No.FS2321774)

Fuel Pump Strainer FS2321774

from

$23.99
CARQUEST Premium electric fuel pumps are built to meet or exceed Original Equipment (OE) specifications for fit, form and function. Our CARQUEST Premium fuel pumps are built to be installed in the Original Equipment module or assembly. We have invested in industry-leading quality upgrades, like upgraded turbine impellers and 100% carbon commutators, to deliver greater reliability. CARQUEST Premium electric fuel pumps are engineered with superior quality components to provide the longest life and reliable performance.

Product Features:
  • Meets or exceeds OE specifications for fit, form and function
  • 100% carbon commutators provide resistance to aggressive fuels and double the life expectancy of the pump
  • OE upgraded turbine impellers greatly reduce fuel pulsation
  • All fuel pumps are 100% performance tested
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Delphi – Electric Fuel Pump and Strainer Set: 12V, With 2 Female Blade Terminals, External Strainer (Part No.FE0388)

Electric Fuel Pump and Strainer Set: 12V, With 2 Female Blade Terminals, External Strainer

from

$175.99
100 years of OE experience, supplier to the world’s top automakers, OE Heritage and knowledge built into every aftermarket part, comprehensive portfolio for a wide range of vehicles and model years.

Product Features:
  • Delphi is a global OE manufacturer and all fuel pumps are built to Delphi’s OE standards
  • Delphi pumps are designed to operate under extreme temperatures with quick engine starts and to avoid low-fuel hesitation, including alcohol fuels and blends
  • Improved pump performance as a result of Delphi’s innovative design and durability
  • Restores fast pressure performance and system integrity, translating to better pumping through less energy
  • Part is validated, tested and matched to the right vehicle application
  • When servicing the fuel system, always check the fuel filter for possible replacement
  • Always be sure to check and clean fuel tank to avoid unnecessary returns
  • Always replace the fuel strainer when doing a fuel pump repair
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Hitachi – Fuel Pump With Filter Screen – New Actual OE Part (Part No.FUP0019)

Fuel Pump With Filter Screen - New Actual OE Part

from

$251.99
Hitachi’s Fuel Pumps (FUPs) are the bloodline of a vehicle’s fuel delivery system, sending a constant supply of pressurized fuel from the tank to the fuel system. Our pumps create and maintain an accurate positive pressure in the fuel lines, pushing fuel to the engine. Using a combination or high strength steel alloy and aluminum, our pumps keep weight at a minimum while increasing reliability. Designed to meet the exact needs of each specific vehicle, Hitachi’s fuel pumps are the premium choice.

Product Features:
  • Disperses fuel accurately; Meets optimal horsepower requirements.
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Carquest Premium – Fuel Cap Tester Adapter (Part No.12422)

Fuel Cap Tester Adapter

from

$39.99
Fuel Cap Tester Adaper for use with Stant fuel cap testers. Color coded for easy identification. Made of durable plastic.

Product Features:
  • BAR Certified adapters
  • Adapter check’s a fuel cap’s ability to hold pressure.
  • Adapters meet EPA standards for recommended fleet coverage.
  • Check adapter application chart for specific makes and models
See More

Spectra Premium – Fuel Pump Strainer (Part No.STR11)

Fuel Pump Strainer

from

$15.49
Innovative engineering, manufacturing technology and quality control ensure that Spectra Premium strainers meet or exceed the performance of the original equipment they replace.

Product Features:
  • Designed with gradient density to meet or exceed OE specifications
  • Engineered and developed in Canada
  • Designed to ensure optimal filtration to prevent fuel system contamination
  • Strainer material tested and validated for capacity and efficiency by accredited, third party
  • Engineered to stringent tolerances based on our Canadian engineers’ in-depth knowledge of the OE part it’s designed to replace
  • Engineered and developed by Spectra Premium; proud member of the A.A.S.A. fuel pump manufacturers working group
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Most Popular 2003 Infiniti QX4 Gas Caps

Customize your Infiniti with 7 Gas Caps products like Gas Caps, all priced under $25.99.

Carquest Premium – Keyed Alike Locking Fuel Cap (Part No.17508)

Keyed Alike Locking Fuel Cap

from

$14.29
None

Product Features:
  • Protects your fuel from theft and vandalism
  • Manufactured from durable, long-life materials
  • Independently tested for emission control
  • Passes all state and federal emissions tests
  • Reduces air pollution with proper sealing and venting
See More

Carquest Premium – Fuel Cap: 10838, Twist-Lock, Direct Fit, Provides Tight Seal, 1 Pack (Part No.10838)

Fuel Cap: 10838, Twist-Lock, Direct Fit, Provides Tight Seal, 1 Pack

from

$17.79
Manufactured with OEM quality materials and safety standards by an OE Supplier. Manufactured to pass all state and federal emissions requirements. Specifically designed pressure and vacuum relief valves to prevent evaporation of fuel. A leaking fuel cap can allow up to 30 gallons of gasoline to evaporate over the period of a year.

Product Features:
  • Passes all state and federal emissions tests
  • Manufactured from durable, long-life materials
  • Reduces air pollution with proper sealing and venting
  • Independently tested for emission control
See More

Carquest Premium – Fuel Cap (Part No.10842)

Fuel Cap

from

$17.79
Manufactured with OEM quality materials and safety standards by an OE Supplier. Manufactured to pass all state and federal emissions requirements. Specifically designed pressure and vacuum relief valves to prevent evaporation of fuel. A leaking fuel cap can allow up to 30 gallons of gasoline to evaporate over the period of a year.

Product Features:
  • Passes all state and federal emissions tests
  • Manufactured from durable, long-life materials
  • Reduces air pollution with proper sealing and venting
  • Independently tested for emission control
See More

Carquest Premium – Locking Fuel Cap: 10508, Twist-Lock, Direct Fit, Provides Tight Seal, 1 Pack (Part No.10508)

Locking Fuel Cap: 10508, Twist-Lock, Direct Fit, Provides Tight Seal, 1 Pack

from

$24.99
Manufactured with OEM quality materials and safety standards by an OE Supplier. Manufactured to pass all state and federal emissions requirements. Specifically designed pressure and vacuum relief valves to prevent evaporation of fuel. A leaking fuel cap can allow up to 30 gallons of gasoline to evaporate over the period of a year.

Product Features:
  • Protects your fuel from theft and vandalism
  • Passes all state and federal emissions tests
  • Manufactured from durable, long-life materials
  • Reduces air pollution with proper sealing and venting
  • Independently tested for emission control
See More

Carquest Premium – Locking Fuel Cap: 10512, Screw On, Direct Fit, Provides Tight Seal, 1 Pack (Part No.10512)

Locking Fuel Cap: 10512, Screw On, Direct Fit, Provides Tight Seal, 1 Pack

from

$24.99
Manufactured with OEM quality materials and safety standards by an OE Supplier. Manufactured to pass all state and federal emissions requirements. Specifically designed pressure and vacuum relief valves to prevent evaporation of fuel. A leaking fuel cap can allow up to 30 gallons of gasoline to evaporate over the period of a year.

Product Features:
  • Protects your fuel from theft and vandalism
  • Passes all state and federal emissions tests
  • Manufactured from durable, long-life materials
  • Reduces air pollution with proper sealing and venting
  • Independently tested for emission control
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Motorad – Tethered Fuel Cap (Part No.MGC837T)

Tethered Fuel Cap

from

$25.99
Manufactured with OEM quality materials and safety standards by an OE Supplier. Manufactured to pass all state and federal emissions requirements. Specifically designed pressure and vacuum relief valves to prevent evaporation of fuel. A leaking fuel cap can allow up to 30 gallons of gasoline to evaporate over the period of a year.

Product Features:
  • Come pre-assembled for quick and easy installation.
  • Several fastener options to work with any fuel cap compartment configuration
  • Fits vehicles orginally equipped with tether
  • Reduces air pollution with proper sealing and venting
  • Manufactured from durable, long-life materials
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Carquest Premium – Keyed Alike Locking Fuel Cap (Part No.17512)

Keyed Alike Locking Fuel Cap

from

$17.49
Manufactured with OEM quality materials and safety standards by an OE Supplier. Manufactured to pass all state and federal emissions requirements. Specifically designed pressure and vacuum relief valves to prevent evaporation of fuel. A leaking fuel cap can allow up to 30 gallons of gasoline to evaporate over the period of a year.

Product Features:
  • Protects your fuel from theft and vandalism
  • Manufactured from durable, long-life materials
  • Independently tested for emission control
  • Passes all state and federal emissions tests
  • Reduces air pollution with proper sealing and venting
See More

Top Picks for 2003 Infiniti QX4 Air Flow Sensors

Upgrade Infiniti QX4s with top-quality Air Flow Sensors parts, including 7 OEM and aftermarket selections for your 2003 model.

Dorman – Nissan Splash Shield Retainer (Part No.961-031D)

Nissan Splash Shield Retainer

from

$4.49
Constructed of quality materials, this multi-purpose retainer provides the same function and versatility as the original equipment retainer ensuring long service life.

Product Features:
  • Ideal replacement – this retainer matches the fit and function of the original equipment retainer for this vehicle application
  • Quality material – this retainer is made of durable material for long-lasting service
  • Versatile design – this retainer is suitable for a variety of automotive uses
  • Excellent value – this part offers original equipment quality at a competitive cost
See More

Niles – Ambient Temp Sensor (Part No.P4025778656NIL)

Ambient Temp Sensor

from

$36.50
Ambient Temp Sensor

Carquest Premium – Coolant Temp Switch (Part No.ECA1919)

Coolant Temp Switch

from

$115.99
The CarQuest Vehicle Solutions line of vehicle electronics are designed for OE form, fit and function for both import and domestic vehicles. The Coolant Temperature Switch monitors the temperature of the engine’s coolant, activating fans at factory designated temperature set-points ensuring proper engine temperature levels and peak engine performance are maintained.

Product Features:
  • Made to OE spec to ensure a proper fit, form and function.
  • Sensors are engineered for precision performance, durability and a long service life.
  • Designed and manufactured with quality materials, industry leading electronic components and strict quality controls. Engineered to meet OE performance.
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Walker – Walker Oxygen Sensor (Part No.C5010402502WKR)

Walker Oxygen Sensor

from

$96.06
Walker Oxygen Sensors are precision made for outstanding performance and manufactured to meet and exceed all original equipment specification and test requirements.

Product Features:
  • Improved Engine Response and Performance
  • Lower Emissions
  • Improved Fuel Economy
  • Longer Sensor Life
  • Meets OEM Specifications Installation Notes: Vehicles equipped with Air Fuel Ratio Sensors may look very similar to the Oxygen Sensor. Please confirm the correct part before ordering and if the connector does not match, do not install
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Carquest Premium – Ambient Air Temperature Sensor (Part No.WTA1186)

Ambient Air Temperature Sensor

from

$43.99
CARQUEST premium engine management products provide the right automatic transmission speed sensor for a wide range of domestic and import applications. Delivering the highest performance and durability under demanding conditions. Designed to meet OE quali

Product Features:
  • Lifecycle tested to meet or exceed OE specifications
  • Direct OE replacement
  • High strength thermoplastic is resistant to shock, temperature and chemicals. Also protects internal components from moisture and contaminants.
  • Global coverage for import and/or domestic applications.
See More

Hitachi – Air Intake Temperature Sensor – New Actual OE Part (Part No.TMS0003)

Air Intake Temperature Sensor - New Actual OE Part

from

$39.49
Hitachi is a Tier One OE supplier to the largest automobile manufacturers globally, delivery industry leading quality, and exceeding customer expectations with our products and service. Hitachi is bringing that same knowledge and expertise to the premium products we deliver in the Aftermarket because Quality Matters. Hitachi’s line of vehicle sensors are crucial to an efficiently operating vehicle. Whether is it an Automatic Transmission Speed Sensor, Crankshaft Angle Sensor, Camshaft Angle Sensor, Knock Sensor, Pressure Sensor, Temperature Sensor, Throttle Position Sensor, or Oil Level Sensor, you can rely on accurate readings and signals to be transmitted to your vehicles’ Electrical Control Unit (ECU) for an efficiently running system. Hitachi uses premium components and materials in the construction of all sensors extending the service interval of the product. Designed to meet the exact needs of each specific vehicle, Hitachi’s Sensors are the premium choice. Hitachi sensor line supports accurate measurement for reliable engine performance.

Product Features:
  • Hitachi is a Tier 1 OE supplier for temperature sensors
  • 100% NEW, never remanufactured
  • Meets the OE performance and durability standards for this application
  • Accurate and reliable measurements
  • Provides accurate measurement; reliable engine performance.
See More

Carquest Premium – Air Charge Temperature Sensor (Part No.WTA1183)

Air Charge Temperature Sensor

from

$30.99
CARQUEST premium engine management products provide the right products for a wide range of domestic and import applications. Delivering the highest performance and durability under demanding conditions.
See More

In-Demand Fuel Injectors for 2003 Infiniti QX4s

Select from 21 premium Fuel Injectors parts for your 2003 Infiniti QX4, with prices ranging from $2.01 to $448.99.

Felpro – Fuel Injection Throttle Body Mounting Gasket (Part No.61342)

Fuel Injection Throttle Body Mounting Gasket

from

$3.29
Fel-Pro gaskets offer 100% vehicle sealing with application-specific materials to give you sealing solutions with the performance and durability professionals trust

Product Features:
  • Meets or exceeds all original equipment specifications
  • Application specific design to ensure a perfect fit
  • Engineered and manufactured specifically for the repair environment
  • Unsurpassed quality you can trust
  • Validated for fit, form, and function
See More

Felpro – Fuel Injector O-Ring Kit (Part No.ES 70599)

Fuel Injector O-Ring Kit

from

$7.49
Fel-Pro gaskets offer 100% vehicle sealing with application-specific materials to give you sealing solutions with the performance and durability professionals trust

Product Features:
  • Meets or exceeds all original equipment specifications
  • Application specific design to ensure a perfect fit
  • Engineered for the sealing repair environment
  • Unsurpassed quality you can trust
  • Validated for fit, form, and function
See More

Carquest – Fuel Injector Connector (Part No.PT2318)

Fuel Injector Connector

from

$4.29
High-quality products that meet OE appearance and performance to provide professional technicians and DIYers with a cost-effective solution.

Product Features:
  • Designed to OE standards for ease of installation
  • All electrical connectors are 100% tested for proper mechanical and electrical fit, form and function
  • Offering thousands of high-quality pigtails & sockets for nearly every electrical job
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Hitachi – Air Flow Sensor – New Actual OE Part (Part No.MAF0092)

Air Flow Sensor - New Actual OE Part

from

$244.99
Hitachis Air Flow Sensors (MAFs) measure the amount and characteristics of air entering the engine. Hitachi uses precision elements and high-quality components for enhanced durability and accurate air flow measurements. Hitachi MAFs are 100% air flow tested for ideal performance and are calibrated for each application ensuring your vehicle meets the strict emission standards set by the manufacturer. Details such as a contaminant bypass port (when applicable) and protected circuitry providing a durable and reliable product approved by OE manufacturers makes Hitachis air flow sensors the premium choice.

Product Features:
  • Hitachi is a Tier 1 OE supplier for air flow sensors
  • 100% NEW, never remanufactured
  • Hitachi’s advanced precision elements and high quality components provide enhanced durability. We feature exact fitment and calibration for each vehicle, which assists engine efficiency and fuel mileage. Our sensors are 100% air flow tested to meet exac
  • Precision manufactured and assembled sensing elements for accurate air flow measurements
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Carquest Premium – Mass Air Flow Sensor (MAF) – 100% NEW (Part No.MQ6247)

Mass Air Flow Sensor (MAF) - 100% NEW

from

$101.99
Advance Auto Parts is proud to carry all new mass air flow sensors that use high-quality components with the highest quality standards.

Product Features:
  • CARQUEST MAF use all new high-quality components at the highest quality standards.
  • Manufactured with new and advanced technology to perform, fit and function at OE specifications.
  • All new product that is tested with OEM equipment to OEM standards
  • Outperforms competition when tested in extreme environmental conditions
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Carquest Premium – Remanufactured Fuel Injector (Part No.A212-2404)

Remanufactured Fuel Injector

from

$49.49
CARQUEST’S line of remanufactured OEM fuel injectors are remanufactured using a proven 15 step process at a state-of-the-art remanufacturing facility in the U.S.A. Each injector is 100% tested under multiple operating conditions to ensure each injector meets or exceeds OE specifications for flow rate, spray pattern, coil resistance, form, fit and function. Each injector includes new external seals and O-rings.

Product Features:
  • Each unit is 100% tested to OE specifications
  • Includes new O-rings and seals made of premium OE quality materials
  • Includes application specific technical bulletin, where applicable
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Hitachi – Fuel Injector – New Actual OE Part (Part No.FIJ0020)

Fuel Injector - New Actual OE Part

from

$81.99
Hitachi’s Fuel Injectors (FIJs) are designed to optimize fuel economy and performance by providing extraordinary accuracy and application specific spray patterns with quick response times. Hitachi’s high-speed electromagnet and pintle precisely control the flow of fuel. High quality materials ensure that even under the most extreme conditions, Hitachi’s FIJs will not deform or malfunction. Our FIJs are 100% flow tested for ideal performance and are calibrated for each application ensuring your vehicle meets the strict emission standards set by the OE manufacturer. Designed to meet the exact needs of each specific vehicle, Hitachi’s Fuel Injectors are the premium choice. Hitachi is a Tier One OE supplier to the largest automobile manufacturers globally, delivering industry leading quality, and exceeding customer expectations with our products and service. Hitachi is bringing that same knowledge and expertise to the premium products we deliver in the Aftermarket because Quality Matters.

Product Features:
  • Hitachi is a Tier 1 OE supplier for fuel injectors
  • 100% NEW, never remanufactured
  • Meets the OE performance and durability standards for this application
  • 100% flow tested for ideal performance
  • High-speed electromagnet and pintle for precise fuel dispersion
  • Application specific spray patterns for optimized fuel efficiency and performance
  • O-Ring included when applicable
See More

Felpro – UPPER INTAKE MANIFOLD GASKET/ PLENUM GASKET (Part No.MS 96455)

UPPER INTAKE MANIFOLD GASKET/ PLENUM GASKET

from

$37.49
Fel-Pro gaskets offer 100% vehicle sealing with application-specific materials to give you sealing solutions with the performance and durability professionals trust

Product Features:
  • Meets or exceeds all original equipment specifications
  • Application specific design to ensure a perfect fit
  • Engineered and manufactured specifically for the repair environment
  • Unsurpassed quality you can trust
  • Each Fel-Pro gasket, no matter how small, is engineered to exacting standards with proprietary design, engineering and manufacturing processes
See More

Carquest – Fuel Injector Seal Kit (Part No.274838)

Fuel Injector Seal Kit

from

$8.99
High-quality products that meet OE appearance and performance to provide professional technicians and DIYers with a cost-effective solution.

Product Features:
  • Designed to OE standards for ease of installation
  • High-quality materials withstand extreme conditions
  • Undergoes extensive testing to ensure reliability
  • As a global manufacturer of automotive aftermarket products, we maintain complete quality control throughout the manufacturing process
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Wells Vehicle Electronics – Fuel Injection Pressure Regulator (Part No.5G1298)

Fuel Injection Pressure Regulator

from

$34.49
WVE is a leading source of advanced vehicle electronics components for replacement applications in the automotive aftermarket and original equipment applications. WVE offers high-technology manufacturing along with innovative solutions and improvements to
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Cardone New – New Mass Air Flow Sensor (Part No.86-10072)

New Mass Air Flow Sensor

from

$448.99
CARDONE Engineered Technology ensures that all CARDONE New Mass Air Flow Sensors precisely track O.E. output curves and maintain strict tolerances to ensure accurate scan tool readings for proper operation. Every component is rated to handle a broad range of environmental conditions, including temperature and altitude.

Product Features:
  • All modules are 100% tested with automated computer test equipment to ensure full functionality and reliability.
  • Our sensors precisely track O.E. output curves and maintain spec tolerances to ensure accurate feedback to the vehicle’s engine control management system.
  • Components are rated to handle demanding temperature variations for optimum reliability in every environment.
  • Guaranteed O.E. fit and function.
See More

Delphi – Mass Air Flow Sensor (Part No.AF10168)

Mass Air Flow Sensor

from

$390.99
100% new; Delphi OE Technology Validated to match the vehicle applications; Manufactured to meet or exceed OE requirements

Product Features:
  • Delphi mass air flow sensors are the global benchmark for accuracy and signal noise
  • Delphi mass air flow sensors feature high quality sensing elements for outstanding performance over a wide range of ambient temperatures
  • Delphi is a manufacturer of OE mass air flow sensors since their first use over 30 years ago
  • All parts are calibrated and tested to match the OE part
  • Probe solution offered wherever possible to reduce repair time by eliminating the need to replace the flow tube.
  • Delphi OE technology validated to match the vehicle applications
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Richporter Technology – Spectra Premium Air Mass Sensor (Part No.B3150253068RPT)

Spectra Premium Air Mass Sensor

from

$193.06
Spectra Premium manufactures a direct fit air mass sensor that guarantees OEM quality, fit and performance.

Product Features:
  • OEM Quality Direct fit Application
  • Platinum coated sensing element
  • Meets or exceeds OEM specifications
  • Utilizes the factory style mounts, connectors and fittings
  • Provides exceptional reliability
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Delphi – Delphi Air Mass Sensor (Part No.B3150468805DEL)

Delphi Air Mass Sensor

from

$180.27
All Delphi Air Mass Sensors feature a patented dimpled flow management feature that provides better control of air separation for more consistent air flow across the sensing elements and enabling outstanding performance in application-specific ducting.

Product Features:
  • Platinum-coated ceramic heated sensing element design is smaller and less fragile than competitive products
  • Heated sensing elements are very robust to damage from dust impingement
  • Heated sensing elements offer proven durability with more that 130 million in the field over the past 16 years
  • Patented temperature compensation algorithm offers robustness to changes in ambient air temperature
  • Patented dimple design eliminates the need for a flow straightener in most applications
  • Probe design offers low restriction air measurement driving increased horsepower
  • Interchangeability is enabled by common mounting footprint
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Hitachi – Hitachi Fuel Injector (Part No.C1000113094HIT)

Hitachi Fuel Injector

from

$158.52
Hitachi fuel injectors are manufactured to OE requirements that meet federal emissions and fuel economy standards, and provide exact OE fit for ease of installation. Hitachi injectors are manufactured using internal components that are compatible with alternative fuels or fuel blends, including ethanol mixtures.

Product Features:
  • Original Equipment Manufacturer
  • Premium internal components
  • OE Calibrated impedance
  • Fine atomized spray reduces emissions
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Delphi – Fuel Injection Pressure Regulator (Part No.FP10406)

Fuel Injection Pressure Regulator

from

$132.99
100 years of OE experience, supplier to the world’s top automakers, OE Heritage and knowledge built into every aftermarket part.

Product Features:
  • Precisely manufactured internal valves, diaphragms and springs means excellent performance under all engine operating conditions
  • Quiet operation, no audible regulator noise
  • Robust diaphragm materials means longer life, improved durability and compatibility with a wide range of fuels
  • Consistent and predictable fuel pressure throughout system range of control provides great drivability
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Victor Reinz – Fuel Injector O-Ring Kit (Part No.18-10027-01)

Fuel Injector O-Ring Kit

from

$8.79
With Victor Reinz gaskets, you can be sure you are getting sealing solutions that deliver OE quality gasket technology and engineering. That is because Victor Reinz is an original equipment supplier and the trusted choice of manufacturers the world over, offering broad coverage for foreign and domestic cars and trucks. In Victor Reinz gasket sets, you get the right combination of components needed for fast, long-lasting repairs.

Product Features:
  • Choosing Victor Reinz assures getting OE quality parts in gaskets sets that have the coverage, contents, packaging and electronic cataloging to best meet the needs of the aftermarket.
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Carquest Premium – Fuel Injector Connector (Part No.PTA1064)

Fuel Injector Connector

from

$4.29
CARQUEST premium engine management products provide the right products for a wide range of domestic and import applications. Delivering the highest performance and durability under demanding conditions.
See More

Ishino – Throttle Body Gasket (Part No.C7001308191ISH)

Throttle Body Gasket

from

$3.44
Throttle Body Gasket

ACDelco – Fuel Injector Fuel Feed and Return Pipe O-Ring Kit with 2 O-Rings (Part No.217-3366)

Fuel Injector Fuel Feed and Return Pipe O-Ring Kit with 2 O-Rings

from

$3.29
The ACDelco Professional Fuel Injector Seal Kit contains high quality aftermarket replacement components for one or more of the following vehicle systems: ignition, and/or engine fuel management. This premium aftermarket kit contains components that are manufactured to meet or exceed your expectations for fit, form, and function.

Product Features:
  • Professional, premium aftermarket replacement
  • Provides the performance and dependability you expect from ACDelco
  • Manufactured to meet expectations for fit, form, and function
See More

Ishino Stone – Fuel Injector O-Ring (Part No.C1012262676ISH)

Fuel Injector O-Ring

from

$2.01
Fuel Injector O-Ring

Most Sold 2003 Infiniti QX4 Oxygen Sensors

Explore our best-selling Infiniti parts for the 2003 QX4 among 22 OEM and aftermarket options starting from $49.99.

Bosch – Oxygen Sensor: 3 Wire, 22.44" Long, Heated, Exact Fit (Part No.13091)

Oxygen Sensor: 3 Wire, 22.44" Long, Heated, Exact Fit

from

$49.99
Bosch is the world’s leading supplier and original equipment manufacturer of Oxygen Sensors. Bosch invented the automotive oxygen sensor and leads the way in sensor technology and innovation. From overall sensor design to the critical ceramic element, Bosch is known worldwide for quality and performance.

Product Features:
  • Premium Bosch oxygen sensors are designed to improve fuel economy while reducing harmful emissions
  • Direct Fit includes OE Connector for easy installation
  • Performance meets or exceeds OE specifications
  • True Direct-fit OE connectors and harness
See More

Bosch – Oxygen Sensor: 4 Wire, 35.83" Long, Heated, Exact Fit (Part No.13650)

Oxygen Sensor: 4 Wire, 35.83" Long, Heated, Exact Fit

from

$89.99
Bosch is the world’s leading supplier and original equipment manufacturer of Oxygen Sensors. Bosch invented the automotive oxygen sensor and leads the way in sensor technology and innovation. From overall sensor design to the critical ceramic element, Bosch is known worldwide for quality and performance.

Product Features:
  • Premium Bosch oxygen sensors are designed to improve fuel economy while reducing harmful emissions
  • Direct Fit includes OE Connector for easy installation
  • Performance meets or exceeds OE specifications
  • True Direct-fit OE connectors and harness
See More

Bosch – Oxygen Sensor: 3 Wire, 17.72" Long, Heated, Exact Fit (Part No.13224)

Oxygen Sensor: 3 Wire, 17.72" Long, Heated, Exact Fit

from

$79.99
Bosch is the world’s leading supplier and original equipment manufacturer of Oxygen Sensors. Bosch invented the automotive oxygen sensor and leads the way in sensor technology and innovation. From overall sensor design to the critical ceramic element, Bosch is known worldwide for quality and performance.

Product Features:
  • Premium Bosch oxygen sensors are designed to improve fuel economy while reducing harmful emissions
  • Direct Fit includes OE Connector for easy installation
  • Performance meets or exceeds OE specifications
  • True Direct-fit OE connectors and harness
See More

Bosch – Oxygen Sensor: 4 Wire, 24.02" Long, Heated, Exact Fit (Part No.15727)

Oxygen Sensor: 4 Wire, 24.02" Long, Heated, Exact Fit

from

$69.99
Bosch is the world’s leading supplier and original equipment manufacturer of Oxygen Sensors. Bosch invented the automotive oxygen sensor and leads the way in sensor technology and innovation. From overall sensor design to the critical ceramic element, Bosch is known worldwide for quality and performance.

Product Features:
  • Premium Bosch oxygen sensors are designed to improve fuel economy while reducing harmful emissions
  • Includes Smart Link Connector, no soldering required
  • No special tools required for installation
  • Seared protection tube due to 100% functional quality test
  • Performance meets or exceeds OE specifications
See More

Bosch – Oxygen Sensor: 3 Wire, 24.02" Long, Heated, Universal (Part No.15726)

Oxygen Sensor: 3 Wire, 24.02" Long, Heated, Universal

from

$69.99
Bosch is the world’s leading supplier and original equipment manufacturer of Oxygen Sensors. Bosch invented the automotive oxygen sensor and leads the way in sensor technology and innovation. From overall sensor design to the critical ceramic element, Bosch is known worldwide for quality and performance.

Product Features:
  • Premium Bosch oxygen sensors are designed to improve fuel economy while reducing harmful emissions
  • Includes Smart Link Connector, no soldering required
  • No special tools required for installation
  • Seared protection tube due to 100% functional quality test
  • Performance meets or exceeds OE specifications
See More

Bosch – Oxygen Sensor: 4 Wire, 47.44" Long, Heated, Exact Fit (Part No.13651)

Oxygen Sensor: 4 Wire, 47.44" Long, Heated, Exact Fit

from

$82.99
Bosch is the world’s leading supplier and original equipment manufacturer of Oxygen Sensors. Bosch invented the automotive oxygen sensor and leads the way in sensor technology and innovation. From overall sensor design to the critical ceramic element, Bosch is known worldwide for quality and performance.

Product Features:
  • Premium Bosch oxygen sensors are designed to improve fuel economy while reducing harmful emissions
  • Direct Fit includes OE Connector for easy installation
  • Performance meets or exceeds OE specifications
  • True Direct-fit OE connectors and harness
See More

DENSO – Oxygen Sensor: 4 Wire, 11.77" Long, Heated, Universal Fit (Part No.234-4700)

Oxygen Sensor: 4 Wire, 11.77" Long, Heated, Universal Fit

from

$80.99
DENSO Oxygen Sensors are manufactured and tested to the strictest OE standards for unparalleled performance. Each component is precision built for exact replacement, and a first time fit. This innovative line features DENSO’s exclusive aluminum oxide trap layer, designed to protect the ceramic element from silicone and lead posining for improved engine performance, greater fuel efficiency, and unparalleled longevity. DENSO gives you the right part and the right fit, the first time.

Product Features:
  • Specifically designed to meet the increasing demands of today’s engines
  • 100% checked for high temperature signal output, air tightness, continuity, and heat resistance for optimal efficiency and performance
  • Coated with aluminum oxide to prevent silicone and lead from contacting the ceramic element and damaging the platinum electrode
  • Double protection cover helps maintain proper unit temperature for quicker response times, which is critical to your vehicle’s fuel efficiency
  • Manufactured with a rugged stainless steel housing and porous PTFE filter to resist corrosion and contamination
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Bosch – Oxygen Sensor: 3 Wire, 28.54" Long, Heated, Universal (Part No.15735)

Oxygen Sensor: 3 Wire, 28.54" Long, Heated, Universal

from

$79.99
Bosch is the world’s leading supplier and original equipment manufacturer of Oxygen Sensors. Bosch invented the automotive oxygen sensor and leads the way in sensor technology and innovation. From overall sensor design to the critical ceramic element, Bosch is known worldwide for quality and performance.

Product Features:
  • Premium Bosch oxygen sensors are designed to improve fuel economy while reducing harmful emissions
  • Includes Smart Link Connector, no soldering required
  • No special tools required for installation
  • Seared protection tube due to 100% functional quality test
  • Performance meets or exceeds OE specifications
See More

NTK – Switching Oxygen Sensor: 4 Wire, 35.5" Long, Heated, Direct Fit (Part No.24573)

Switching Oxygen Sensor: 4 Wire, 35.5" Long, Heated, Direct Fit

from

$92.99
NTK is the world’s largest supplier and manufacturer of OEM oxygen sensors. Oxygen sensors play a critical role as part of the vehicle’s on-board diagnostic system in maintaining optimal engine performance, maximizing fuel efficiency and reducing harmful emissions. Providing constant closed loop feedback to the ECU, oxygen sensors help to control the air-fuel ratio while alerting OBDII systems of possible problems with fuel delivery or catalytic converter efficiency. A ceramics company at our core, NTK uses state-of-the art technology enabling control of the ceramic element used in our oxygen sensors from raw material to finished product. Trust The Sensor Specialist for full-line market support and OE application technology.

Product Features:
  • OEM QUALITY: NTK is the world’s largest supplier of original equipment oxygen sensors with renowned quality that meets or exceeds OEM specifications
  • PRODUCT ENGINEERING: Based on OE expertise, but specifically engineered for the aftermarket, NTK Oxygen Sensors offer superior OE fit, form, function
  • OE TECHNOLOGY: Upgraded to the latest OE technologies, NTK Oxygen Sensors are designed to reduce OE failures, enhance durability and performance
  • EXTENSIVE TESTING: OE development includes vibration and thermal shock testing. Testing during manufacturing guarantees quality and reliability
  • EASY INSTALLATION: NTK Oxygen Sensors are equipped with OE specified, water-resistant connectors and harness accessory hardware for easy installation
  • ADVANCED CERAMIC SENSOR ELEMENT: 3-stage contaminant-resistant plasma jet and deposit trap overcoat protects against element poisoning
  • NTK ADVANTAGE: Superior dual-coated platinum interface and thinner ceramic element produces fastest light off and response times with best durability
See More

Walker – Walker Oxygen Sensor (Part No.C5010402422WKR)

Walker Oxygen Sensor

from

$88.61
Walker Oxygen Sensors are precision made for outstanding performance and manufactured to meet and exceed all original equipment specification and test requirements.

Product Features:
  • Improved Engine Response and Performance
  • Lower Emissions
  • Improved Fuel Economy
  • Longer Sensor Life
  • Meets OEM Specifications Installation Notes: Vehicles equipped with Air Fuel Ratio Sensors may look very similar to the Oxygen Sensor. Please confirm the correct part before ordering and if the connector does not match, do not install
See More

NTK – Switching Oxygen Sensor: 4 Wire, 47.75" Long, Heated, Direct Fit (Part No.24643)

Switching Oxygen Sensor: 4 Wire, 47.75" Long, Heated, Direct Fit

from

$100.99
NTK is the world’s largest supplier and manufacturer of OEM oxygen sensors. Oxygen sensors play a critical role as part of the vehicle’s on-board diagnostic system in maintaining optimal engine performance, maximizing fuel efficiency and reducing harmful emissions. Providing constant closed loop feedback to the ECU, oxygen sensors help to control the air-fuel ratio while alerting OBDII systems of possible problems with fuel delivery or catalytic converter efficiency. A ceramics company at our core, NTK uses state-of-the art technology enabling control of the ceramic element used in our oxygen sensors from raw material to finished product. Trust The Sensor Specialist for full-line market support and OE application technology.

Product Features:
  • OEM QUALITY: NTK is the world’s largest supplier of original equipment oxygen sensors with renowned quality that meets or exceeds OEM specifications
  • PRODUCT ENGINEERING: Based on OE expertise, but specifically engineered for the aftermarket, NTK Oxygen Sensors offer superior OE fit, form, function
  • OE TECHNOLOGY: Upgraded to the latest OE technologies, NTK Oxygen Sensors are designed to reduce OE failures, enhance durability and performance
  • EXTENSIVE TESTING: OE development includes vibration and thermal shock testing. Testing during manufacturing guarantees quality and reliability
  • EASY INSTALLATION: NTK Oxygen Sensors are equipped with OE specified, water-resistant connectors and harness accessory hardware for easy installation
  • ADVANCED CERAMIC SENSOR ELEMENT: 3-stage contaminant-resistant plasma jet and deposit trap overcoat protects against element poisoning
  • NTK ADVANTAGE: Superior dual-coated platinum interface and thinner ceramic element produces fastest light off and response times with best durability
See More

Bosch – Oxygen Sensor (Part No.15343)

Oxygen Sensor

from

$114.99
Bosch is the world’s leading supplier and original equipment manufacturer of Oxygen Sensors. Bosch invented the automotive oxygen sensor and leads the way in sensor technology and innovation. From overall sensor design to the critical ceramic element, Bosch is known worldwide for quality and performance.

Product Features:
  • Premium Bosch oxygen sensors are designed to improve fuel economy while reducing harmful emissions
  • Direct Fit includes OE Connector for easy installation
  • Performance meets or exceeds OE specifications
  • True Direct-fit OE connectors and harness
  • Performance meets or exceeds OE specifications
See More

NTK – NTK Oxygen Sensor (Part No.C5010381301NTK)

NTK Oxygen Sensor

from

$233.36
NTK is the world’s largest supplier and manufacturer of original equipment oxygen sensors. NTK oxygen sensors meet or exceed original equipment specifications and are equipped with waterproof factory fitted connectors to ensure a perfect fit every time. Every NTK oxygen sensor is individually tested to ensure the highest level of quality and reliability.

Product Features:
  • OE-Equivalent.
  • Direct fit for easy installation.
  • Extensively Tested During Manufacture to Guarantee Quality and Reliability
  • Supplied With a Factory-Fitted OEM Connector for Easy Installation
See More

DENSO – First Time Fit Oxygen Sensor (Part No.C5010331528ND)

First Time Fit Oxygen Sensor

from

$198.86
Denso First Time Fit oxygen sensors are constructed of the highest quality materials available. High-quality stainless steel, porous polytetrafluoroethylene (PTFE), fluorine rubber, aluminum oxide, high-grade platinum and ceramics are used in each DENSO sensor.

Product Features:
  • SUPERIOR DESIGN – Maximizes engine performance and fuel efficiency while reducing harmful emissions.
  • DOUBLE-PROTECTION COVER – Maintains proper unit temperature for quicker response times and protects the ceramic element against silicone and lead poisoning.
  • ALUMINUM-OXIDE TRAP LAYER – Keeps silicone and lead outside the ceramic element through DENSO’s exclusive design, preventing damage to the platinum electrode.
  • STAINLESS STEEL HOUSING – Resists corrosion and contamination with a rugged, watertight body.
See More

NTK – Switching Oxygen Sensor: 3 Wire, 19.75" Long, Heated, Direct Fit (Part No.24618)

Switching Oxygen Sensor: 3 Wire, 19.75" Long, Heated, Direct Fit

from

$161.99
NTK is the world’s largest supplier and manufacturer of OEM oxygen sensors. Oxygen sensors play a critical role as part of the vehicle’s on-board diagnostic system in maintaining optimal engine performance, maximizing fuel efficiency and reducing harmful emissions. Providing constant closed loop feedback to the ECU, oxygen sensors help to control the air-fuel ratio while alerting OBDII systems of possible problems with fuel delivery or catalytic converter efficiency. A ceramics company at our core, NTK uses state-of-the art technology enabling control of the ceramic element used in our oxygen sensors from raw material to finished product. Trust The Sensor Specialist for full-line market support and OE application technology.

Product Features:
  • OEM QUALITY: NTK is the world’s largest supplier of original equipment oxygen sensors with renowned quality that meets or exceeds OEM specifications
  • PRODUCT ENGINEERING: Based on OE expertise, but specifically engineered for the aftermarket, NTK Oxygen Sensors offer superior OE fit, form, function
  • OE TECHNOLOGY: Upgraded to the latest OE technologies, NTK Oxygen Sensors are designed to reduce OE failures, enhance durability and performance
  • EXTENSIVE TESTING: OE development includes vibration and thermal shock testing. Testing during manufacturing guarantees quality and reliability
  • EASY INSTALLATION: NTK Oxygen Sensors are equipped with OE specified, water-resistant connectors and harness accessory hardware for easy installation
  • ADVANCED CERAMIC SENSOR ELEMENT: 3-stage contaminant-resistant plasma jet and deposit trap overcoat protects against element poisoning
  • NTK ADVANTAGE: Superior dual-coated platinum interface and thinner ceramic element produces fastest light off and response times with best durability
See More

DENSO – First Time Fit Oxygen Sensor (Part No.C5010121569ND)

First Time Fit Oxygen Sensor

from

$144.12
Denso First Time Fit oxygen sensors are constructed of the highest quality materials available. High-quality stainless steel, porous polytetrafluoroethylene (PTFE), fluorine rubber, aluminum oxide, high-grade platinum and ceramics are used in each DENSO sensor.

Product Features:
  • SUPERIOR DESIGN – Maximizes engine performance and fuel efficiency while reducing harmful emissions.
  • DOUBLE-PROTECTION COVER – Maintains proper unit temperature for quicker response times and protects the ceramic element against silicone and lead poisoning.
  • ALUMINUM-OXIDE TRAP LAYER – Keeps silicone and lead outside the ceramic element through DENSO’s exclusive design, preventing damage to the platinum electrode.
  • STAINLESS STEEL HOUSING – Resists corrosion and contamination with a rugged, watertight body.
See More

DENSO – First Time Fit Oxygen Sensor (Part No.C5010121682ND)

First Time Fit Oxygen Sensor

from

$137.70
Denso First Time Fit oxygen sensors are constructed of the highest quality materials available. High-quality stainless steel, porous polytetrafluoroethylene (PTFE), fluorine rubber, aluminum oxide, high-grade platinum and ceramics are used in each DENSO sensor.

Product Features:
  • SUPERIOR DESIGN – Maximizes engine performance and fuel efficiency while reducing harmful emissions.
  • DOUBLE-PROTECTION COVER – Maintains proper unit temperature for quicker response times and protects the ceramic element against silicone and lead poisoning.
  • ALUMINUM-OXIDE TRAP LAYER – Keeps silicone and lead outside the ceramic element through DENSO’s exclusive design, preventing damage to the platinum electrode.
  • STAINLESS STEEL HOUSING – Resists corrosion and contamination with a rugged, watertight body.
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NTK – Switching Oxygen Sensor: 3 Wire, 36" Long, Heated, Direct Fit (Part No.24528)

Switching Oxygen Sensor: 3 Wire, 36" Long, Heated, Direct Fit

from

$106.99
NTK is the world’s largest supplier and manufacturer of OEM oxygen sensors. Oxygen sensors play a critical role as part of the vehicle’s on-board diagnostic system in maintaining optimal engine performance, maximizing fuel efficiency and reducing harmful emissions. Providing constant closed loop feedback to the ECU, oxygen sensors help to control the air-fuel ratio while alerting OBDII systems of possible problems with fuel delivery or catalytic converter efficiency. A ceramics company at our core, NTK uses state-of-the art technology enabling control of the ceramic element used in our oxygen sensors from raw material to finished product. Trust The Sensor Specialist for full-line market support and OE application technology.

Product Features:
  • OEM QUALITY: NTK is the world’s largest supplier of original equipment oxygen sensors with renowned quality that meets or exceeds OEM specifications
  • PRODUCT ENGINEERING: Based on OE expertise, but specifically engineered for the aftermarket, NTK Oxygen Sensors offer superior OE fit, form, function
  • OE TECHNOLOGY: Upgraded to the latest OE technologies, NTK Oxygen Sensors are designed to reduce OE failures, enhance durability and performance
  • EXTENSIVE TESTING: OE development includes vibration and thermal shock testing. Testing during manufacturing guarantees quality and reliability
  • EASY INSTALLATION: NTK Oxygen Sensors are equipped with OE specified, water-resistant connectors and harness accessory hardware for easy installation
  • ADVANCED CERAMIC SENSOR ELEMENT: 3-stage contaminant-resistant plasma jet and deposit trap overcoat protects against element poisoning
  • NTK ADVANTAGE: Superior dual-coated platinum interface and thinner ceramic element produces fastest light off and response times with best durability
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DENSO – Oxygen Sensor: Upstream, 3 Wire, 36.02" Long, Heated, Exact Fit (Part No.234-3106)

Oxygen Sensor: Upstream, 3 Wire, 36.02" Long, Heated, Exact Fit

from

$103.99
DENSO Oxygen Sensors are manufactured and tested to the strictest OE standards for unparalleled performance. Each component is precision built for exact replacement, and a first time fit. This innovative line features DENSO’s exclusive aluminum oxide trap layer, designed to protect the ceramic element from silicone and lead posining for improved engine performance, greater fuel efficiency, and unparalleled longevity. DENSO gives you the right part and the right fit, the first time.

Product Features:
  • Specifically designed to meet the increasing demands of today’s engines
  • 100% checked for high temperature signal output, air tightness, continuity, and heat resistance for optimal efficiency and performance
  • Coated with aluminum oxide to prevent silicone and lead from contacting the ceramic element and damaging the platinum electrode
  • Double protection cover helps maintain proper unit temperature for quicker response times, which is critical to your vehicle’s fuel efficiency
  • Manufactured with a rugged stainless steel housing and porous PTFE filter to resist corrosion and contamination
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DENSO – Oxygen Sensor: Downstream, 4 Wire, 47.83" Long, Heated, Exact Fit (Part No.234-4713)

Oxygen Sensor: Downstream, 4 Wire, 47.83" Long, Heated, Exact Fit

from

$99.99
DENSO Oxygen Sensors are manufactured and tested to the strictest OE standards for unparalleled performance. Each component is precision built for exact replacement, and a first time fit. This innovative line features DENSO’s exclusive aluminum oxide trap layer, designed to protect the ceramic element from silicone and lead posining for improved engine performance, greater fuel efficiency, and unparalleled longevity. DENSO gives you the right part and the right fit, the first time.

Product Features:
  • Specifically designed to meet the increasing demands of today’s engines
  • 100% checked for high temperature signal output, air tightness, continuity, and heat resistance for optimal efficiency and performance
  • Coated with aluminum oxide to prevent silicone and lead from contacting the ceramic element and damaging the platinum electrode
  • Double protection cover helps maintain proper unit temperature for quicker response times, which is critical to your vehicle’s fuel efficiency
  • Manufactured with a rugged stainless steel housing and porous PTFE filter to resist corrosion and contamination
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DENSO – Oxygen Sensor: 3 Wire, 11.77" Long, Heated, Universal Fit (Part No.234-3090)

Oxygen Sensor: 3 Wire, 11.77" Long, Heated, Universal Fit

from

$82.99
DENSO Oxygen Sensors are manufactured and tested to the strictest OE standards for unparalleled performance. Each component is precision built for exact replacement, and a first time fit. This innovative line features DENSO’s exclusive aluminum oxide trap layer, designed to protect the ceramic element from silicone and lead posining for improved engine performance, greater fuel efficiency, and unparalleled longevity. DENSO gives you the right part and the right fit, the first time.

Product Features:
  • Specifically designed to meet the increasing demands of today’s engines
  • 100% checked for high temperature signal output, air tightness, continuity, and heat resistance for optimal efficiency and performance
  • Coated with aluminum oxide to prevent silicone and lead from contacting the ceramic element and damaging the platinum electrode
  • Double protection cover helps maintain proper unit temperature for quicker response times, which is critical to your vehicle’s fuel efficiency
  • Manufactured with a rugged stainless steel housing and porous PTFE filter to resist corrosion and contamination
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Bosch – Universal Oxygen Sensor (Part No.C5010100327BOS)

Universal Oxygen Sensor

from

$60.32
The Bosch universal oxygen sensor utilizes a mix of zirconium and yttrium oxides and other elements to form a tough base that withstands the intense stress to which oxygen sensors are subjected. Each element is incredibly strong for best-in-class performance and maximum service life. From overall sensor design to the critical ceramic element, Bosch is known worldwide for quality and performance.

Product Features:
  • OE-Equivalent.
  • Direct fit for easy installation.
  • OE Style connectors and wire lengths.
  • Base ceramic probe of Zirconium and Yttrium.
  • Patented Platinum Power Grid.
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Top-Rated Fuel and Emissions Systems Brands For Your 2003 Infiniti QX4

Shop for the best-rated brands offering Fuel and Emissions Systems and other products for your 2003 Infiniti QX4s. Below you’ll find some of our best rated Fuel and Emissions Systems from FELPRO and Carquest Premium, and more. Fuel and Emissions Systems from these brands that fit a 2003 QX4 start at just $3.29 and are rated as high as 5 stars. OEM and aftermarket Fuel and Emissions Systems don’t get more top quality, durable, and affordable than from the brands below.

Popular FELPRO 2003 Infiniti QX4 Fuel and Emissions Systems

When it comes to maintaining or upgrading your 2003 Infiniti QX4, using quality Fuel and Emissions Systems is essential to ensure durability and a perfect fit. FELPRO ticks all of those boxes. We offer a wide selection of FELPRO Fuel and Emissions Systems, specifically designed for the 2003 Infiniti QX4. With over 3 FELPRO brand Fuel and Emissions Systems in stock, you’re sure to find what you need. The prices for these top-notch parts start as low as $3.29, with an average price of just $16.09. Plus, with over 110 customer reviews and an average rating of 5 stars, you can trust that our FELPRO Fuel and Emissions Systems will get the job done right. Choose Advance Auto Parts for reliability, quality, and expert-approved parts that keep your vehicle running strong.

Fuel Injector O-Ring Kit
from
$7.49

(109)

Fuel Injector O-Ring Kit

“Replaced the boring in my TBSS fuel injectors and there is no more leaks.”

UPPER INTAKE MANIFOLD GASKET/ PLENUM GASKET
from
$37.49
This product is not rated

UPPER INTAKE MANIFOLD GASKET/ PLENUM GASKET

“”

Fuel Injection Throttle Body Mounting Gasket
from
$3.29

(1)

Fuel Injection Throttle Body Mounting Gasket

“Great fit”

Popular Carquest Premium 2003 Infiniti QX4 Fuel and Emissions Systems

Carquest Premium auto parts is one of the highest quality Fuel and Emissions System brands in the market. Any 2003 Infiniti QX4 owner should feel confident when installing genuine Carquest Premium parts in their vehicle. To ensure the best fit and performance for your 2003 QX4, Advance Auto Parts carries a full inventory of 23 Carquest Premium Fuel and Emissions Systems. Plus you will be keeping your Infiniti in peak condition while saving money because prices on these Carquest Premium Fuel and Emissions Systems range from $4.29 to $195.99, plus, with more than 307 customer reviews and an impressive 4 stars average rating, you can be confident the Fram Fuel and Emissions Systems below will deliver on both quality and value.

Mass Air Flow Sensor (MAF) - 100% NEW
from
$101.99
This product is not rated

Mass Air Flow Sensor (MAF) – 100% NEW

“”

Fuel Pump Tank Seal TS3541966
from
$6.49
This product is not rated

Fuel Pump Tank Seal TS3541966

“”

Fuel Pump Strainer FS2321774
from
$23.99
This product is not rated

Fuel Pump Strainer FS2321774

“”

FAQs for 2003 Infiniti QX4 Fuel and Emissions Systems

Which Fuel and Emissions Systems are best-sellers for 2003 Infiniti QX4s?

Out of 88 Fuel and Emissions Systems that fit 2003 Infiniti QX4s, the following parts are the top sellers:

What’s the price range for 2003 Infiniti QX4 Fuel and Emissions Systems?

Fuel and Emissions System prices for the 2003 Infiniti QX4 start at $1.85 and go up to $448.99 for the most premium parts.

What’s the average price of a Fuel and Emissions System for a 2003 Infiniti QX4?

The average price for Fuel and Emissions Systems for the 2003 Infiniti QX4 is $92.96. Keep in mind the variety of part types within our Fuel and Emissions System category so you are likely to find a wide range of prices across a variety of parts and components.

Does Advance Auto Parts sell Fuel and Emissions Systems for other Infiniti QX4 model years?

Yes, we currently carry Fuel and Emissions Systems for 6 model years of Infiniti QX4s between 1997 and 2002. Fuel and Emissions Systems are bought most frequently for the following model years: 2002, 2001, 2000, 1999, 1998, and 1997.

What are the cheapest Fuel and Emissions Systems for my 2003 Infiniti QX4?

The cheapest 2003 Infiniti QX4 Fuel and Emissions Systems we carry in stock are:

What types of Fuel and Emissions Systems do you sell for my 2003 Infiniti QX4?

Can I get help with 2003 Infiniti QX4 Fuel and Emissions System orders?

Contact our customer support team, by chat or phone, through the help desk page, where you can find instant answers about Infiniti Fuel and Emissions Systems and more.

What is your return policy for Infiniti QX4 Fuel and Emissions Systems?

Advance Auto Parts keeps returns simple. For new Infiniti QX4 Fuel and Emissions Systems and accessories, your online orders can be returned, in their original condition, within 45 days. For requirements, see the returns page.