Chevrolet City Express Air- Fuel Ratio Sensors

Your Chevrolet City Express will be happy to know that the search for the right Air- Fuel Ratio Sensors you’ve been looking for is over! Advance Auto Parts has 2 different Air- Fuel Ratio Sensors for your vehicle, ready for shipping or in-store pick up. The best part is, our Chevrolet City Express Air- Fuel Ratio Sensors start from as little as $156.99.

When it comes to your Chevrolet City Express, you want parts and products from only trusted brands. Here at Advance Auto Parts, we work with only top reliable Air- Fuel Ratio Sensors brands so you can shop with complete confidence. Some of our top Air- Fuel Ratio Sensors brands are DENSO and NTK. We’re sure you will get the right product to keep that City Express running for a long time.

Shop online, find the best price on the right product, and have it shipped right to your door. If you prefer to shop in person for the right Air- Fuel Ratio Sensors for your City Express, visit one of our local Advance Auto Parts locations and you’ll be back on the road in no time!

Compare 25 Chevrolet Air- Fuel Ratio Sensors

DENSO – First Time Fit Oxygen Sensor (Part No.C5010422568ND)

First Time Fit Oxygen Sensor

from

$61.18
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

Bosch – Bosch Oxygen Sensor (Part No.C5010379534BOS)

Bosch Oxygen Sensor

from

$66.02
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.
See More

Walker – Walker Oxygen Sensor (Part No.C5010380306WKR)

Walker Oxygen Sensor

from

$65.44
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

DENSO – First Time Fit Oxygen Sensor (Part No.C5010118198ND)

First Time Fit Oxygen Sensor

from

$59.26
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

Bosch – Bosch Oxygen Sensor (Part No.C5010147361BOS)

Bosch Oxygen Sensor

from

$47.62
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.
See More

DENSO – First Time Fit Oxygen Sensor (Part No.C5010392962ND)

First Time Fit Oxygen Sensor

from

$63.89
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 – NTK Oxygen Sensor (Part No.C5010379969NTK)

NTK Oxygen Sensor

from

$155.68
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
  • Precision manufactured with a sensing element incorporating NTK’s premier technical ceramics 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

Bosch – Bosch Oxygen Sensor (Part No.C501089595BOS)

Bosch Oxygen Sensor

from

$101.38
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.
See More

ACDelco – GM Original Equipment Oxygen Sensor (Part No.C5010205454ACD)

GM Original Equipment Oxygen Sensor

from

$82.29
The ACDelco GM Original Equipment Oxygen (O2) Sensor is a GM-recommended replacement for your vehicle’s original component. The Oxygen (O2) Sensor is a special feedback sensor on your vehicle’s exhaust system. This sensor measures the proportion of oxygen in the exhaust gases. Using this measurement, the engine management computer can adjust the air/fuel ratio near the optimum value of 14.7:1. At this ratio, engine performance, emissions, and fuel economy are all optimized. This original equipment oxygen sensor has been manufactured to fit your specific GM vehicle, providing the same performance, durability, and service life you expect from General Motors. When you are looking for a match to GM Original Equipment specifications in a replacement part for your GM vehicle, trust ACDelco to get the job done.

Product Features:
  • Detect oxygen content in the exhaust gases to optimize emissions and fuel economy
  • GM-recommended replacement part for your GM vehicle’s original factory component
  • Offering the quality, reliability, and durability of GM OE
  • Manufactured to GM OE specification for fit, form, and function
See More

DENSO – Wideband Oxygen Sensor: Upstream, 4 Wire, 18.23" Long, Heated, Exact Fit (Part No.234-9135)

Wideband Oxygen Sensor: Upstream, 4 Wire, 18.23" Long, Heated, Exact Fit

from

$238.99
DENSO Air/Fuel Ratio 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. DENSO gives you the right part and the right fit the first t

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
See More

ACDelco – GM Original Equipment Oxygen Sensor (Part No.C5010465670ACD)

GM Original Equipment Oxygen Sensor

from

$80.10
The ACDelco GM Original Equipment Oxygen (O2) Sensor is a GM-recommended replacement for your vehicle’s original component. The Oxygen (O2) Sensor is a special feedback sensor on your vehicle’s exhaust system. This sensor measures the proportion of oxygen in the exhaust gases. Using this measurement, the engine management computer can adjust the air/fuel ratio near the optimum value of 14.7:1. At this ratio, engine performance, emissions, and fuel economy are all optimized. This original equipment oxygen sensor has been manufactured to fit your specific GM vehicle, providing the same performance, durability, and service life you expect from General Motors. When you are looking for a match to GM Original Equipment specifications in a replacement part for your GM vehicle, trust ACDelco to get the job done.

Product Features:
  • Detect oxygen content in the exhaust gases to optimize emissions and fuel economy
  • GM-recommended replacement part for your GM vehicle’s original factory component
  • Offering the quality, reliability, and durability of GM OE
  • Manufactured to GM OE specification for fit, form, and function
See More

ACDelco – GM Original Equipment Oxygen Sensor (Part No.C5010205230ACD)

GM Original Equipment Oxygen Sensor

from

$63.65
The ACDelco GM Original Equipment Oxygen (O2) Sensor is a GM-recommended replacement for your vehicle’s original component. The Oxygen (O2) Sensor is a special feedback sensor on your vehicle’s exhaust system. This sensor measures the proportion of oxygen in the exhaust gases. Using this measurement, the engine management computer can adjust the air/fuel ratio near the optimum value of 14.7:1. At this ratio, engine performance, emissions, and fuel economy are all optimized. This original equipment oxygen sensor has been manufactured to fit your specific GM vehicle, providing the same performance, durability, and service life you expect from General Motors. When you are looking for a match to GM Original Equipment specifications in a replacement part for your GM vehicle, trust ACDelco to get the job done.

Product Features:
  • Detect oxygen content in the exhaust gases to optimize emissions and fuel economy
  • GM-recommended replacement part for your GM vehicle’s original factory component
  • Offering the quality, reliability, and durability of GM OE
  • Manufactured to GM OE specification for fit, form, and function
See More

DENSO – First Time Fit Oxygen Sensor (Part No.C5010100877ND)

First Time Fit Oxygen Sensor

from

$51.24
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

ACDelco – GM Original Equipment Oxygen Sensor (Part No.C5010377980ACD)

GM Original Equipment Oxygen Sensor

from

$96.34
The ACDelco GM Original Equipment Oxygen (O2) Sensor is a GM-recommended replacement for your vehicle’s original component. The Oxygen (O2) Sensor is a special feedback sensor on your vehicle’s exhaust system. This sensor measures the proportion of oxygen in the exhaust gases. Using this measurement, the engine management computer can adjust the air/fuel ratio near the optimum value of 14.7:1. At this ratio, engine performance, emissions, and fuel economy are all optimized. This original equipment oxygen sensor has been manufactured to fit your specific GM vehicle, providing the same performance, durability, and service life you expect from General Motors. When you are looking for a match to GM Original Equipment specifications in a replacement part for your GM vehicle, trust ACDelco to get the job done.

Product Features:
  • Detect oxygen content in the exhaust gases to optimize emissions and fuel economy
  • GM-recommended replacement part for your GM vehicle’s original factory component
  • Offering the quality, reliability, and durability of GM OE
  • Manufactured to GM OE specification for fit, form, and function
See More

ACDelco – Oxygen Sensor (Part No.C5010581052ACD)

Oxygen Sensor

from

$84.39
Oxygen Sensor

NTK – Wideband Oxygen Sensor: Air-Fuel Ratio 4 Wire, 15" Long, Heated, Direct Fit (Part No.24783)

Wideband Oxygen Sensor: Air-Fuel Ratio 4 Wire, 15" Long, Heated, Direct Fit

from

$156.99
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. While conventional switching oxygen sensors only switch rich or lean, wideband oxygen (or Air-Fuel Ratio) sensors produce a linear output signal that allows the ECU determine exactly how rich or lean an engine is running and make continuous and precise adjustments of the air-fuel mixture to stay closest to stoichiometric, providing the best possible combustion and fewest emissions. A ceramics company at our core, NTK uses state-of-the art technology enabling complete control of the ceramics used in our wideband 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

ACDelco – GM Original Equipment Oxygen Sensor (Part No.C5010435169ACD)

GM Original Equipment Oxygen Sensor

from

$71.24
The ACDelco GM Original Equipment Oxygen (O2) Sensor is a GM-recommended replacement for your vehicle’s original component. The Oxygen (O2) Sensor is a special feedback sensor on your vehicle’s exhaust system. This sensor measures the proportion of oxygen in the exhaust gases. Using this measurement, the engine management computer can adjust the air/fuel ratio near the optimum value of 14.7:1. At this ratio, engine performance, emissions, and fuel economy are all optimized. This original equipment oxygen sensor has been manufactured to fit your specific GM vehicle, providing the same performance, durability, and service life you expect from General Motors. When you are looking for a match to GM Original Equipment specifications in a replacement part for your GM vehicle, trust ACDelco to get the job done.

Product Features:
  • Detect oxygen content in the exhaust gases to optimize emissions and fuel economy
  • GM-recommended replacement part for your GM vehicle’s original factory component
  • Offering the quality, reliability, and durability of GM OE
  • Manufactured to GM OE specification for fit, form, and function
See More

DENSO – First Time Fit Oxygen Sensor (Part No.C5010118192ND)

First Time Fit Oxygen Sensor

from

$54.90
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

Bosch – Oxygen Sensor (Part No.C501017643BOS)

Oxygen Sensor

from

$69.21
Oxygen Sensor

ACDelco – Oxygen Sensor (Part No.C5010445693ACD)

Oxygen Sensor

from

$88.31
The ACDelco GM Original Equipment Oxygen (O2) Sensor is a GM-recommended replacement for your vehicle’s original component. The Oxygen (O2) Sensor is a special feedback sensor on your vehicle’s exhaust system. This sensor measures the proportion of oxygen in the exhaust gases. Using this measurement, the engine management computer can adjust the air/fuel ratio near the optimum value of 14.7:1. At this ratio, engine performance, emissions, and fuel economy are all optimized. This original equipment oxygen sensor has been manufactured to fit your specific GM vehicle, providing the same performance, durability, and service life you expect from General Motors. When you are looking for a match to GM Original Equipment specifications in a replacement part for your GM vehicle, trust ACDelco to get the job done.

Product Features:
  • Detect oxygen content in the exhaust gases to optimize emissions and fuel economy
  • GM-recommended replacement part for your GM vehicle’s original factory component
  • Offering the quality, reliability, and durability of GM OE
  • Manufactured to GM OE specification for fit, form, and function
See More

NTK – NTK Oxygen Sensor (Part No.C5010400246NTK)

NTK Oxygen Sensor

from

$70.25
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

NTK – Wideband Oxygen Sensor: Air-Fuel Ratio 5 Wire, 14.75" Long, Heated, Direct Fit (Part No.27016)

Wideband Oxygen Sensor: Air-Fuel Ratio 5 Wire, 14.75" Long, Heated, Direct Fit

from

$59.99
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. While conventional switching oxygen sensors only switch rich or lean, wideband oxygen (or Air-Fuel Ratio) sensors produce a linear output signal that allows the ECU determine exactly how rich or lean an engine is running and make continuous and precise adjustments of the air-fuel mixture to stay closest to stoichiometric, providing the best possible combustion and fewest emissions. A ceramics company at our core, NTK uses state-of-the art technology enabling complete control of the ceramics used in our wideband 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.C5010380294WKR)

Walker Oxygen Sensor

from

$91.15
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

ACDelco – Oxygen Sensor (Part No.C5010307790ACD)

Oxygen Sensor

from

$94.59
The ACDelco GM Original Equipment Oxygen (O2) Sensor is a GM-recommended replacement for your vehicle’s original component. The Oxygen (O2) Sensor is a special feedback sensor on your vehicle’s exhaust system. This sensor measures the proportion of oxygen in the exhaust gases. Using this measurement, the engine management computer can adjust the air/fuel ratio near the optimum value of 14.7:1. At this ratio, engine performance, emissions, and fuel economy are all optimized. This original equipment oxygen sensor has been manufactured to fit your specific GM vehicle, providing the same performance, durability, and service life you expect from General Motors. When you are looking for a match to GM Original Equipment specifications in a replacement part for your GM vehicle, trust ACDelco to get the job done.

Product Features:
  • Detect oxygen content in the exhaust gases to optimize emissions and fuel economy
  • GM-recommended replacement part for your GM vehicle’s original factory component
  • Offering the quality, reliability, and durability of GM OE
  • Manufactured to GM OE specification for fit, form, and function
See More

DENSO – First Time Fit Oxygen Sensor (Part No.C5010302452ND)

First Time Fit Oxygen Sensor

from

$75.91
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

FAQs for Chevrolet City Express Air- Fuel Ratio Sensors

What are the most popular Air- Fuel Ratio Sensors for the Chevrolet City Express?

With 2 brands you can trust, our most popular Air- Fuel Ratio Sensors for the Chevrolet City Express are:
Wideband Oxygen Sensor: Upstream, 4 Wire, 18.23" Long, Heated, Exact Fit
from $238.99
This product is not rated
Wideband Oxygen Sensor: Upstream, 4 Wire, 18.23" Long, Heated, Exact Fit
Air- Fuel Ratio Sensors
Wideband Oxygen Sensor: Air-Fuel Ratio 4 Wire, 15" Long, Heated, Direct Fit
from $156.99
This product is not rated
Wideband Oxygen Sensor: Air-Fuel Ratio 4 Wire, 15" Long, Heated, Direct Fit
Air- Fuel Ratio Sensors