2021 Subaru WRX STI Fuel and Emissions Systems

Name: Vapor Canister Purge Solenoid: Includes Mounting Hardware
Brand: Carquest Premium
SKU: CPC1423
Price: 88.99 USD

Below you will find various in-demand Subaru Fuel and Emissions Systems, components and accessories for your 2021 WRX STI. Advance Auto Parts has popular WRX STI parts like Gas Caps, Fuel Injectors, Fuel Tanks and more. You’ll also find aftermarket and OEM Fuel and Emissions Systems for other WRX STI model years including 2015, 2016, 2017, 2018, 2019, 2020 and more. Select a category of 2021 Subaru WRX STI Fuel and Emissions Systems below and start saving instantly.

Popular 2021 Subaru WRX STI Fuel and Emissions Systems Categories

Air- Fuel Ratio Sensors

Fuel Tank Cleaning Kits

Air Flow Meters and Mass Air

Gas Caps

Oxygen Sensors

Canister Purge Solenoids

EGR Valves

Fuel Injectors

Ambient Air Temperature Sensors

Fuel Injector O-Ring Kits

Fuel Injector Seal Kits

EGR Valve Gaskets

Essential Fuel and Emissions Systems for 2021 Subaru WRX STIs

from

$88.99

Maximize your vehicle’s efficiency and emissions control with Carquest Vapor Canister Purge Solenoids. Engineered for precision, these solenoids seamlessly regulate the flow of fuel vapors from the Vapor Canister to the engine for cleaner combustion, reducing harmful emissions. Built to meet and/or exceed OEM standards, Carquest Purge Solenoids offer reliable functionality, long-lasting durability, and easy installation.

Product Features:

Enhances overall engine performance by providing proper vapor flow to maintain correct air-fuel mixture.
Helps reduce harmful emissions and ensures compliance with environmental regulations by controlling the release of fuel vapors into the engine
Ensures precise operation with electromagnetic principles to control the flow of fuel vapors from the carbon canister to the engine
Manufactured from high quality engineered materials, resistant to fuel vapors and extreme temperatures, ensuring long lasting performance
Meets or exceeds all OEM specifications

from

$48.49

Enhances overall engine performance by providing proper vapor flow to maintain correct air-fuel mixture.
Helps reduce harmful emissions and ensures compliance with environmental regulations by controlling the release of fuel vapors into the engine
Ensures precise operation with electromagnetic principles to control the flow of fuel vapors from the carbon canister to the engine
Manufactured from high quality engineered materials, resistant to fuel vapors and extreme temperatures, ensuring long lasting performance
Meets or exceeds all OEM specifications

from

$5.99

Fel-Pro gaskets are specifically designed for the repair environment to deliver a reliable seal on even the most troublesome applications. Designed for imperfect sealing surfaces and manufactured with proprietary materials, you can count on Fel-Pro for innovative sealing solutions for the real-world repair environment.

Product Features:

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

from

$4.49

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

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 poisoning for improved engine performance, greater fuel efficiency, and unparalleled longevity. DENSO gives you the right part and the right fit.

Product Features:

Specifically designed to meet the increasing demands of today’s engines
100 percent 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

from

$115.99

NGK 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, 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: 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, Oxygen Sensors offer superior OE fit, form, function
OE TECHNOLOGY: Upgraded to the latest OE technologies, 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: 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
ADVANTAGE: Superior dual-coated platinum interface and thinner ceramic element produces fastest light off and response times with best durability

from

$74.99

The temperature of various systems must be reported to the engine control module (ECM) as well as other operating system controllers in the vehicle. Coolant temperature, cabin temperature, exhaust temperature and ambient temperature are just a few systems reported by a temperature sensor. The temperature sensor is fed 5 volts by the systems computer, within the sensor housing will be a thermistor, or dropping resistor whose resistance value will change as the temperature surrounding it changes. Changing resistance in the circuit will change the volt signal at the processor indicating the current operating value.

Product Features:

Product constructed to meet all design and operating characteristics as intended by the vehicle manufacturer.
100% thermo-shock and vibration tested to ensure superior performance in extreme conditions.
100% end-of-line tested to ensure accurate signal output providing product reliability, every time.
Tin plated lead frame prevents corrosion and ensures a reliable terminal connection under adverse ambient conditions.
Lead frame terminal size and location determined using image dimension measuring system or 3D laser scanner.
Application matched components ensures system operation in like new condition.

from

$7.99

CARQUEST fuel injector seal kits include the necessary O-rings and seals to properly reseal the injector, which is a recommended practice any time the injector is removed. Each kit services one injector and includes hard to find or previously dealer-only components.

Product Features:

Premium OE quality materials
Services one injector

from

$79.99

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

from

$201.99

DENSO Air/Fuel Ratio Sensors are manufactured and tested to the strictest OE standards for unparalleled peformance.; Each component is precision-built for exact replacement¿ and a first time fit.; 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 percent 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

from

$23.99

Product Features:

Protects your fuel from theft and vandalism
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

from

$21.79

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:

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

from

$7.99

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

from

$154.99

Carquest Premium exhaust gas recirculation (EGR) valves are designed to perform in harsh engine environments and meet or exceed original equipment (O.E.) specifications. Our Carquest Premium EGR valves are built by manufacturers that meet IATF 16949 certified framework, an internationally recognized proof of quality in the automotive industry. Carquest Premium EGR valves undergo extensive validation testing to ensure long-lasting performance and reliability. Carquest Premium EGR valves are part of our Carquest Vehicle Solutions, which is a full line of engine management and electronics products that help control ignition, fuel delivery and emission systems. Carquest Vehicle Solutions are OE-quality parts designed, engineered and tested by world-class manufacturers to ensure a reliable and long-lasting repair.

Product Features:

Designed to meet or exceed OE specifications for fit, form and function
Precision engineering and robust design to withstand harsh under hood environment
Gaskets or seals are included if required for installation
Extensive design validation testing and 100% end-of-line tested
Where applicable stainless-steel sleeves used over cold rolled sleeves providing smooth EGR pintle operation under all operating conditions.
Carquest Vehicle Solutions Technical Support available from ASE certified technicians: 1-866-687-5413

from

$13.99

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

from

$7.49

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

from

$191.99

Every single Delphi mass air flow (MAF) sensor that we manufacture – whether with or without the housing – is built with calibrated all-new components and is never remanufactured. Our mass air flow sensors are designed and tested to meet or exceed OE requirements, and engineered for a perfect fit in more than 180 million vehicles on the road today in North America – including makes from Ford, Toyota, Nissan, Volkswagen, Hyundai, BMW, Honda, GM, Mazda, Subaru, Acura and more.

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

from

$90.99

CARQUEST MAF sensors are 100% new and are produced by a certified OEM supplier that designs and manufactures new mass air flow sensors

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

from

$177.99

DENSO’s innovated designs reduces the size and weight which allows for easy installation. Glass film coated sensing elements reduces contamination exposure and improves reliability.

Product Features:

OE technology adapted for the aftermarket
Reduces emissions, increased performance
Delivers the highest reliability and detection accuracy

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

Upgrade your 2021 Subaru WRX STI with Top-Quality Fuel and Emissions Systems

When it comes to maintaining or upgrading your 2021 Subaru WRX STI, nothing is more important than using high-quality OEM or aftermarket parts that you can trust. Whether you’re repairing damage to your Subaru or enhancing its overall performance, Fuel and Emissions Systems are key to keeping your WRX STI functioning at its best. At Advance Auto Parts, we offer a wide selection of 28 Fuel and Emissions Systems for the 2021 Subaru WRX STI, designed to meet your needs without breaking the bank. From Gas Cap replacements to Fuel Injectors 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 2021 Subaru WRX STI at great prices. Our Fuel and Emissions Systems inventory for this model ranges from just $2.29 to $201.99, with an average price of $53.94. Our 28 Fuel and Emissions Systems in stock come from 6 trusted brands, so you’re sure to find the right part for your 2021 Subaru WRX STI 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 2021 Subaru WRX STI, we stock popular OEM and aftermarket Fuel and Emissions Systems from top names like DENSO Carquest Premium, and more. DENSO Fuel and Emissions Systems start at just $103.99 and boast an impressive 4.6 stars average rating from customers. With 1,382 customer reviews and counting, our 2021 Subaru WRX STI 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 2021 Subaru WRX STI is always ready to roll. We’re committed to providing you with everything you need to keep your WRX STI in top shape, all in one place. Start shopping confidently below for your 2021 Subaru WRX STI!

Best-Selling Gas Caps for 2021 Subaru WRX STIs

Enhance the driving experience in your Subaru with 11 quality Gas Cap components, starting at $7.99.

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from

$11.99

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

from

$14.99

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

from

$15.49

Product Features:

Reduces air pollution with proper sealing and venting
Manufactured from durable, long-life materials
Reduces air pollution with proper sealing and venting
Independently tested for emission control

from

$15.99

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

from

$23.99

Product Features:

Protects your fuel from theft and vandalism
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

from

$21.79

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

from

$22.99

Product Features:

Protects your fuel from theft and vandalism
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

from

$7.99

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

from

$24.29

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

from

$11.79

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

from

$10.99

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

Top Picks for 2021 Subaru WRX STI Fuel Tanks

Upgrade Subaru WRX STIs with top-quality Fuel Tanks parts, including 1 OEM and aftermarket selections for your 2021 model.

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from

$12.49

Helps avoid premature fuel pump failure
Lint free towel included
Low suds formulation
Removes harmful contaminants from the fuel tank

In-Demand Oxygen Sensors for 2021 Subaru WRX STIs

Select from 2 premium Oxygen Sensors parts for your 2021 Subaru WRX STI, with prices ranging from $72.99 to $103.99.

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from

$103.99

Specifically designed to meet the increasing demands of today’s engines
100 percent 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

from

$72.99

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

Most Sold 2021 Subaru WRX STI Air Flow Sensors

Explore our best-selling Subaru parts for the 2021 WRX STI among 2 OEM and aftermarket options starting from $74.99.

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from

$201.99

Specifically designed to meet the increasing demands of today’s engines
100 percent 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

from

$74.99

Product constructed to meet all design and operating characteristics as intended by the vehicle manufacturer.
100% thermo-shock and vibration tested to ensure superior performance in extreme conditions.
100% end-of-line tested to ensure accurate signal output providing product reliability, every time.
Tin plated lead frame prevents corrosion and ensures a reliable terminal connection under adverse ambient conditions.
Lead frame terminal size and location determined using image dimension measuring system or 3D laser scanner.
Application matched components ensures system operation in like new condition.

Top-Rated Fuel and Emissions Systems Brands For Your 2021 Subaru WRX STI

Shop for the best-rated brands offering Fuel and Emissions Systems and other products for your 2021 Subaru WRX STIs. Below you’ll find some of our best rated Fuel and Emissions Systems from DENSO and Carquest Premium, and more. Fuel and Emissions Systems from these brands that fit a 2021 WRX STI start at just $11.99 and are rated as high as 4.6 stars. OEM and aftermarket Fuel and Emissions Systems don’t get more top quality, durable, and affordable than from the brands below.

Popular DENSO 2021 Subaru WRX STI Fuel and Emissions Systems

When it comes to maintaining or upgrading your 2021 Subaru WRX STI, using quality Fuel and Emissions Systems is essential to ensure durability and a perfect fit. DENSO ticks all of those boxes. We offer a wide selection of DENSO Fuel and Emissions Systems, specifically designed for the 2021 Subaru WRX STI. With over 2 DENSO 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 $103.99, with an average price of just $140.99. Plus, with over 333 customer reviews and an average rating of 4.6 stars, you can trust that our DENSO 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.

from $103.99

(332)

Oxygen Sensor: Downstream, 4 Wire, 21.26" Long, Heated, Exact Fit

“Easy fit first time.”

from $177.99

(1)

Mass Air Flow Sensor

“Could not have been easier — one connector and 2 Phillips screws — done! Used the same day delivery service and could not be more pleased!”

Popular Carquest Premium 2021 Subaru WRX STI Fuel and Emissions Systems

Carquest Premium auto parts is one of the highest quality Fuel and Emissions System brands in the market. Any 2021 Subaru WRX STI owner should feel confident when installing genuine Carquest Premium parts in their vehicle. To ensure the best fit and performance for your 2021 WRX STI, Advance Auto Parts carries a full inventory of 3 Carquest Premium Fuel and Emissions Systems. Plus you will be keeping your Subaru in peak condition while saving money because prices on these Carquest Premium Fuel and Emissions Systems range from $11.99 to $15.49, plus, with more than 182 customer reviews and an impressive 4.4 stars average rating, you can be confident the Fram Fuel and Emissions Systems below will deliver on both quality and value.

from $14.99

(37)

Fuel Cap: Round, Direct Fit, Provides Tight Seal, 1 Pack

“Works Great”

from $15.49

(142)

Non-Locking Fuel Tank Cap

“Good”

from $11.99

(3)

Keyed Alike Locking Fuel Cap

“Worked fine”

FAQs for 2021 Subaru WRX STI Fuel and Emissions Systems

Which Fuel and Emissions Systems are best-sellers for 2021 Subaru WRX STIs?

Out of 28 Fuel and Emissions Systems that fit 2021 Subaru WRX STIs, the following parts are the top sellers:

Fuel Cap: Round, Direct Fit, Provides Tight Seal, 1 Pack (18481528) – $14.99
Non-Locking Tethered Fuel Tank Cap (12102600) – $24.29
Fuel Injector Seal Kit (11450352) – $7.99

What’s the price range for 2021 Subaru WRX STI Fuel and Emissions Systems?

Fuel and Emissions System prices for the 2021 Subaru WRX STI start at $2.29 and go up to $201.99 for the most premium parts.

What’s the average price of a Fuel and Emissions System for a 2021 Subaru WRX STI?

The average price for Fuel and Emissions Systems for the 2021 Subaru WRX STI is $53.94. 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 Subaru WRX STI model years?

Yes, we currently carry Fuel and Emissions Systems for 5 model years of Subaru WRX STIs between 2015 and 2020. Fuel and Emissions Systems are bought most frequently for the following model years: 2020, 2019, 2018, 2017, 2016, and 2015.

What are the cheapest Fuel and Emissions Systems for my 2021 Subaru WRX STI?

The cheapest 2021 Subaru WRX STI Fuel and Emissions Systems we carry in stock are:

Exhaust Gas Recirculation (EGR) Valve Gasket (50263184) – $2.29
Exhaust Gas Recirculation (EGR) Valve Gasket (20688239) – $4.49
Exhaust Gas Recirculation (EGR) Valve Gasket (50192360) – $5.99
Fuel Injector O-Ring Kit (12045004) – $7.49
Fuel Injector Seal Kit (11450352) – $7.99

What are the top-rated Fuel and Emissions Systems that fit the 2021 Subaru WRX STI?

Out of 1,382 reviews by customers, our 2021 Subaru WRX STI Fuel and Emissions Systems have an average customer rating of . These are some of the highest-rated Fuel and Emissions System types for the 2021 Subaru WRX STI and their top-rated products:

Oxygen Sensors
- Oxygen Sensor: Downstream, 4 Wire, 21.26" Long, Heated, Exact Fit (20471856) – $103.99

What types of Fuel and Emissions Systems do you sell for my 2021 Subaru WRX STI?

As of 11/2/25, these are some of the most in-demand types of Fuel and Emissions Systems for a 2021 Subaru WRX STI:

Can I get help with 2021 Subaru WRX STI 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 Subaru Fuel and Emissions Systems and more.

What is your return policy for Subaru WRX STI Fuel and Emissions Systems?

Advance Auto Parts keeps returns simple. For new Subaru WRX STI 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.

2021 Subaru WRX STI Fuel and Emissions Systems

Carquest Premium – Vapor Canister Purge Solenoid: Includes Mounting Hardware (Part No.CPC1423)

Carquest Premium – Vapor Canister Purge Solenoid: Includes Mounting Hardware (Part No.CPA2501)

Felpro – Exhaust Gas Recirculation (EGR) Valve Gasket (Part No.73451)

Felpro – Exhaust Gas Recirculation (EGR) Valve Gasket (Part No.71218)

DENSO – Oxygen Sensor: Downstream, 4 Wire, 21.26" Long, Heated, Exact Fit (Part No.234-4732)

NTK – Switching Oxygen Sensor: 4 Wire, 27.5" Long, Heated, Direct Fit (Part No.24642)

Carquest Premium – Ambient Air Temperature Sensor (Part No.WTA1299)

Carquest Premium – Fuel Injector Seal Kit (Part No.AS024A)

Carquest Premium – Reman Multi Port Fuel Injector (Part No.A212-3414)

DENSO – Wideband Oxygen Sensor: Upstream, 4 Wire, 31.06" Long, Heated, Exact Fit (Part No.234-9034)

Carquest Premium – Locking Fuel Tank Cap (Part No.10591)

Carquest Premium – Locking Fuel Cap: Screw On, Direct Fit, Provides Tight Seal, 1 Pack (Part No.10504)

Carquest Premium – Keyed Alike Locking Fuel Cap (Part No.17504)

Carquest Premium – EGR Valve (Part No.EGC1654)

Felpro – Fuel Injector O-Ring Kit (Part No.ES 73204)

Felpro – Fuel Injector O-Ring Kit (Part No.ES 73202)

Delphi – Mass Air Flow Sensor (Part No.AF10345)

Carquest Premium – Mass Air Flow Sensor (MAF) – 100% NEW (Part No.MQ6398)

DENSO – Mass Air Flow Sensor (Part No.197-6130)

Delphi – Fuel Tank Cleaning Kit (Part No.FC01)

Carquest Premium – Keyed Alike Locking Fuel Cap (Part No.17591)

Carquest Premium – Fuel Cap: Round, Direct Fit, Provides Tight Seal, 1 Pack (Part No.10837)

Carquest Premium – Non-Locking Fuel Tank Cap (Part No.10834)

Carquest Premium – Gas Cap: Twist On, Reduces Air Pollution, 1 Pack (Part No.10817)

Carquest Premium – Locking Fuel Tank Cap (Part No.10591)

Carquest Premium – Locking Fuel Cap: Screw On, Direct Fit, Provides Tight Seal, 1 Pack (Part No.10504)

Carquest Premium – Locking Fuel Tank Cap (Part No.10507)

Carquest Premium – Keyed Alike Locking Fuel Cap (Part No.17504)

Motorad – Non-Locking Tethered Fuel Tank Cap (Part No.MGC817T)

Carquest Premium – Keyed Alike Locking Fuel Cap (Part No.17507)

Carquest Premium – Keyed Alike Locking Fuel Cap (Part No.17505)

DENSO – Mass Air Flow Sensor (Part No.197-6130)

Carquest Premium – Fuel Injector Seal Kit (Part No.AS024A)

Carquest Premium – Mass Air Flow Sensor (MAF) – 100% NEW (Part No.MQ6398)

Felpro – Fuel Injector O-Ring Kit (Part No.ES 73202)

Carquest Premium – Reman Multi Port Fuel Injector (Part No.A212-3414)

Delphi – Mass Air Flow Sensor (Part No.AF10345)

Delphi – Fuel Tank Cleaning Kit (Part No.FC01)

DENSO – Oxygen Sensor: Downstream, 4 Wire, 21.26" Long, Heated, Exact Fit (Part No.234-4732)

Bosch – Oxygen Sensor: 4 Wire, 25.87" Long, Heated, Universal (Part No.15741)

DENSO – Wideband Oxygen Sensor: Upstream, 4 Wire, 31.06" Long, Heated, Exact Fit (Part No.234-9034)

Carquest Premium – Ambient Air Temperature Sensor (Part No.WTA1299)