Air Fuel Ratio Sensor [11 Best Car Air Fuel Ratio Sensors]

One of the major components found on many modern engine management systems is an air fuel ratio sensor. More than one air fuel ratio sensor is found in most vehicles. They’re mounted before and after the catalytic converter in the exhaust system.

Air fuel ratio sensors continuously monitor the vehicle’s exhaust air fuel ratio and send a precise signal to the engine control computer, allowing it to make real-time fuel and timing adjustments for maximum economy and power. What are the best air fuel ratio sensors?

Our top 11 best air fuel ratio sensors are as follows:

  1. Denso 234-9023 Air Fuel Ratio Sensor Click here to see it on Amazon – Our #1 Top Pick!
  2. Walker Products 250-54013 Air/Fuel Ratio Sensor – Click here to see it on Amazon
  3. Denso 234-9002 Air Fuel Ratio Sensor
  4. Denso 234-9010 Air Fuel Ratio Sensor
  5. Denso 234-9047 Air Fuel Ratio Sensor
  6. Denso 234-5700 Air and Fuel Ratio Sensor
  7. Denso 234-9051 Air Fuel Ratio Sensor
  8. Denso 234-9028 Air and Fuel Ratio Sensor
  9. Walker Products 250-54050 Air Fuel Ratio Sensor
  10. Denso 234-9009 Air Fuel Ratio Sensor
  11. Denso 234-9015 Air Fuel Ratio Sensor

Read on to learn more about the 11 best air fuel ratio sensors, including the specs and features for each.

Also, take a look at our top pick on Amazon, the Denso 234-9023 Air Fuel Ratio Sensor, to see its great reviews and price:

Click here to see it on Amazon.

Air Fuel Ratio Sensor [11 Best Car Air Fuel Ratio Sensors]

1. Denso 234-9023 Air Fuel Ratio Sensor

First on our list of the best air fuel ratio sensors is the Denso 234-9023 Air Fuel Ratio Sensor:

Click here to see it on Amazon.

The Denso 234-9023 is designed to help reduce fuel consumption and harmful emissions. It’s made with state-of-the-art sensor technologies and corrosion-resistant stainless steel construction. 

This air fuel ratio sensor is guaranteed to deliver OE quality and reliability. It’s proven to provide dependable service for years ahead. The Denso 234-9023 is compatible with the 2001-2003 Toyota RAV4.

  • O2 sensor configuration: Direct fit
  • Position: Upstream driver side
  • Sensor Type: Heated
  • Connector Gender: Male
  • Wires Quantity: 4 wire leads
  • Wire Harness Length: 15.35″ (389.9 mm)
  • Thread Diameter: 0.71″ (18 mm) 

2. Walker Products 250-54013 Air/Fuel Ratio Sensor

Next on our list of the best air fuel ratio sensors is the Walker Products 250-54013 Air/Fuel Ratio Sensor:

Click here to see it on Amazon.

The Walker Products 250-54013 is designed to meet or exceed OE specifications in form, fit, and function. It provides direct fit replacement and increases fuel economy as well as lower emissions. 

It’s also designed with unparalleled craftsmanship and thoroughly tested to live up to the toughest conditions. It adheres to the highest quality standards as well.

Walker Products 250-54013 vehicle fitment: 2002-2004 Acura RSX, 2001-2005 Honda Civic, and 2002-2004 CR-V.

  • Location: B1S1 sensor
  • Position: Upstream
  • Sensor type: Heated
  • Connector gender: Male
  • Wires quantity: 4 wire leads
  • Thread diameter: 0.71″(18.0 mm)
  • Wire harness length: 11.34″(288.036 mm)
  • Overall length: 14.88″(377.952 mm)
  • Wire gauge measurement: 20 gauge

3. Denso 234-9002 Air Fuel Ratio Sensor

The Denso 234-9002 – Air Fuel Ratio Sensor is another best air fuel ratio sensor on our list:

Click here to see it on Amazon.

This air fuel ratio sensor from Denso is also made of corrosion- and abrasion-resistant substances and uses a zirconia solid electrolyte with an alumina heater substrate.

The Denso 234-9002 is compatible with the 1999-2002 Toyota 4Runner and the 2000-2003 Tacoma.

  • Wire length: 330mm/13″
  • Connector type: OE type
  • Mounting type: Flanged
  • Material: Zirconium
  • Heated: Yes
  • Number of wires: 4
  • Sensor type: Thimble
  • Warranty: 1 year

4. Denso 234-9010 Air Fuel Ratio Sensor

Next on our list of the best air fuel ratio sensor from the same manufacturer is the Denso 234-9010 Air Fuel Ratio Sensor:

Click here to see it on Amazon.

Replace your failing fuel-ratio sensors with this top-notch Denso product to ensure your engine operates effectively and creates fewer emissions. 

This A/F sensor is a fantastic way to regulate engine performance and emissions, as they are designed using cutting-edge sensor technology. You can trust its excellent fit and function in your car since it delivers OE quality and reliability.

Denso 234-9010 vehicle fitment: 2001-2004 Subaru Outback, 2000-2001 Toyota Camry, and 2000-2001 Solara.

  • O2 sensor configuration: Direct fit
  • Position: Upstream
  • Heated sensor type
  • Male connector 
  • 4 wire leads
  • 20.47″ (519.9 mm) wire harness length
  • 0.71″ (18 mm) thread diameter

5. Denso 234-9047 Air Fuel Ratio Sensor

Another best air fuel ratio sensor on our list is the Denso 234-9047 Air Fuel Ratio Sensor:

Click here to see it on Amazon.

With fuel prices increasing and emission standards tightening, it’s more crucial than ever to ensure that the right ratio of air and fuel is maintained. 

Denso oxygen and fuel ratio sensors are an excellent way to improve engine performance while lowering fuel consumption and pollutants. 

Denso 234-9047 vehicle fitment: Lexus ES 2002-2003, Subaru Legacy 2008-2009, Outback 2005-2009, Tribeca 2006-2009, Toyota 4Runner 2003-2004, and Camry 2002-2006.

  • O2 sensor configuration: Direct fit
  • Position: Upstream rear
  • Sensor Type: Heated
  • Male connector gender
  • 4 wire leads
  • Wire harness length: 7.87″ (199.9 mm)
  • Thread diameter: 0.71″ (18 mm) 

6. Denso 234-5700 Air and Fuel Ratio Sensor

The Denso 234-5700 Air and Fuel Ratio Sensor is next on our list for the best air fuel ratio sensor:

Click here to see it on Amazon.

Planar sensors like the Denso 234-5700 use the same zirconia ceramic sensing technology as their predecessors, the thimble sensor, but in a compact version. The heater and small sensing elements are housed in the sensor’s small, thin, flat tip, allowing for a more compact and power-efficient design.

The sensor’s smaller size allows it to be used in tighter, more compact spaces. Five or more wires are used in wideband planar sensors. OE standards are met or exceeded by Denso wideband A/F sensors.

The Denso 234-5700 is compatible with select 2000-2009 Volvo vehicles.

  • Thread diameter: .711″
  • Wire length: 1194mm/47″
  • Connector type: OE type
  • Threaded mounting type
  • Zirconium material
  • Heated: Yes
  • Number of wires: 5
  • Sensor type: Planar
  • Warranty: 1 year

7. Denso 234-9051 Air Fuel Ratio Sensor

Next on our list of the best air fuel ratio sensor is the Denso 234-9051 Air Fuel Ratio Sensor:

Click here to see it on Amazon.

This A/F ratio sensor from Denso fits select vehicles from Lexus and Toyota. Denso 234-9051 vehicle fitment: Lexus GS 2006-2011, GX 2005-2009, IS 2006-2008, LS 2008-2013, and LX 2005-2007; Toyota 4Runner 2005-2009, FJ Cruiser 2007, Land Cruiser 2005-2007, Sequoia 2005-2007, Tacoma 2005-2006, and Tundra 2005-2007.

  • O2 sensor configuration: Direct fit
  • Position: Upstream
  • Sensor type: Heated
  • Connector gender: Male
  • Wires quantity: 4 wire leads
  • Wire harness length: 8.66″ (220 mm)
  • Thread diameter: 0.71″ (18 mm)

8. Denso 234-9028 Air and Fuel Ratio Sensor

The Denso 234-9028 Air and Fuel Ratio Sensor is another top choice on our best air fuel ratio sensor list:

Click here to see it on Amazon.

The Denso 234-9028 – Air Fuel Ratio Sensor is compatible with the 2001-2003 Toyota RAV4.

  • O2 sensor configuration: Direct fit
  • Position: Upstream passenger side
  • Sensor type: Heated
  • Male connector 
  • 4 wire leads
  • Wire harness length: 11.81″ (300 mm)
  • Thread Diameter: 0.71″ (18 mm)

9. Walker Products 250-54050 Air Fuel Ratio Sensor

Next on our list for the best air fuel ratio sensors is the Walker Products 250-54050 Air Fuel Ratio Sensor:

Click here to see it on Amazon.

The Walker Products 250-54050 A/F ratio sensor is compatible with select Lexus and Toyota vehicles.

Walker Products 250-54050 vehicle fitment: Lexus GS 2006-2011, GX 2005-2013, HS 2010-2012, IS 2006-2014, LS 2007-2016, and LX 2005-2011; Toyota 4Runner 2005-2012, 2015-2020, FJ Cruiser 2007-2012, Highlander 2008-2010, Land Cruiser 2005-2011, Sequoia 2005-2012, Tacoma 2005-2008, and Tundra 2005-2013.

  • Position: Upstream passenger side
  • Sensor type: Heated
  • Connector gender: Male
  • 4 wire leads
  • Wire harness length: 8.39″ (213.106 mm)
  • Overall length: 11.93″ (303.022 mm)
  • Thread diameter: 0.71″ (18.0 mm)
  • Wire gauge measurement: 20 gauge

10. Denso 234-9009 Air Fuel Ratio Sensor

The Denso 234-9009 Air Fuel Ratio Sensor made it on our list of the best air fuel ratio sensors:

Click here to see it on Amazon.

The Denso 234-9009 is compatible with select Toyota and Lexus vehicles. Denso 234-9009 vehicle fitment: Lexus ES 1999 and RX 1999-2003; Toyota Avalon 1997-1999, Camry 1999-2000, Highlander 2001-2003, Sienna 1999-2000, and Solara 1999-2000.

  • O2 sensor configuration: Direct fit
  • Upstream front position
  • Sensor type: Heated
  • Male connector
  • Wire quantity: 4 wire leads
  • Wire harness length: 14.17″ (359.9 mm)
  • Thread diameter: 0.71″ (18 mm)

11. Denso 234-9015 Air Fuel Ratio Sensor

Next on our list of the best air fuel ratio sensor, which is also from the same manufacturer, is the Denso 234-9015 Air Fuel Ratio Sensor:

Click here to see it on Amazon.

The Denso 234-9015 – Air Fuel Ratio Sensor fits select Subaru vehicles. It is compatible with the Subaru Baja 2003-2006, Forester 2003-2004, Impreza 2003-2004, Legacy 2003-2004, and Outback 2003-2004.

  • Direct fit O2 sensor configuration
  • Upstream position
  • Sensor type: Heated
  • Female connector
  • 4 wire leads
  • 20.47″ (519.9 mm) wire harness length
  • Thread diameter: 0.71″ (18 mm)

Air Fuel Ratio Sensor [11 Best Car Air Fuel Ratio Sensors]

So to recap, what is the best air fuel ratio sensor? Our top 11 picks for the best air fuel ratio sensor are as follows:

  1. Denso 234-9023 Air Fuel Ratio Sensor Click here to see it on Amazon – Our #1 Top Pick!
  2. Walker Products 250-54013 Air/Fuel Ratio Sensor – Click here to see it on Amazon
  3. Denso 234-9002 Air Fuel Ratio Sensor
  4. Denso 234-9010 Air Fuel Ratio Sensor
  5. Denso 234-9047 Air Fuel Ratio Sensor
  6. Denso 234-5700 Air and Fuel Ratio Sensor
  7. Denso 234-9051 Air Fuel Ratio Sensor
  8. Denso 234-9028 Air and Fuel Ratio Sensor
  9. Walker Products 250-54050 Air Fuel Ratio Sensor
  10. Denso 234-9009 Air Fuel Ratio Sensor
  11. Denso 234-9015 Air Fuel Ratio Sensor