Denso 234-5739 Air / Fuel Ratio Sensor - Upstream or Upstream Left

Denso OE-Style Air/Fuel Ratio Sensor

Denso 234-5739 is a specific-fit, wide-band air/fuel ratio sensor built for direct replacement in select Audi and Volkswagen applications. It is engineered to match OE-style fitment and signal requirements for accurate exhaust feedback and dependable drivability.

This Denso Air / Fuel Ratio Sensor - OE Style is a standard replacement part with a 5-wire design and a 26.57-inch wiring harness length. It is made for upstream locations and is listed for upstream left applications where specified, including Audi Q3, RS3, RS5, S6, S7 Sportback, TT Quattro, TTS Quattro, TT RS Quattro, and Volkswagen Arteon, Jetta, GTI, and Golf R.

Key Features

• Part number 234-5739 OE-style air/fuel ratio sensor
• Wide-band sensor type for upstream exhaust monitoring
• Specific fit for direct replacement applications
• 5-wire configuration with 26.57-inch wiring harness length
• Standard replacement grade for OE-style service
• Fits select Audi and Volkswagen upstream positions

Fitment Details

• Fits 2019-2024 Audi Q3, Upstream
• Fits 2022-2024 Audi RS3, Upstream
• Fits 2017-2020 Audi RS3, Upstream
• Fits 2021-2024 Audi RS5, Upstream Left
• Fits 2018-2019 Audi RS5, Upstream Left
• Fits 2021-2024 Audi RS5 Sportback, Upstream Left
• Fits 2019 Audi RS5 Sportback, Upstream Left
• Fits 2020-2024 Audi S6, Upstream Left
• Fits 2020-2024 Audi S7 Sportback, Upstream Left
• Fits 2019-2023 Audi TT Quattro, Upstream
• Fits 2019-2023 Audi TTS Quattro, Upstream
• Fits 2018-2022 Audi TT RS Quattro, Upstream
• Fits 2019-2022 Volkswagen Arteon, Upstream
• Fits 2019-2022 Volkswagen Jetta, Upstream
• Fits 2020-2021 Volkswagen GTI, Upstream
• Fits 2020 Audi A3 Quattro, Upstream
• Fits 2019-2020 Audi S3, Upstream
• Fits 2019 Audi A3, Upstream
• Fits 2019 Volkswagen Golf R, Upstream

What It Helps Address

• Incorrect air-fuel ratio readings from a worn upstream sensor
• Check engine lights related to oxygen or mixture monitoring faults
• Rough idle or inconsistent throttle response caused by inaccurate feedback
• Fuel trim issues that can affect drivability and emissions performance
• OE-style replacement needs for Audi and Volkswagen turbocharged applications

Installation Notes

Confirm the connector style, wire count, and upstream position before installation. This part is a specific-fit replacement, so matching the vehicle application and sensor location is important for proper operation. For fitment-based searches, this part is commonly selected for Audi Q3 upstream sensor replacement, Volkswagen Jetta upstream sensor replacement, and Audi RS5 upstream left sensor replacement.

Part number 234-5739 cross-references 06K906265C and 06M906265A for the same application.

Quality Assurance

Denso manufactures and tests this sensor to OE standards, with precision-built components intended to deliver exact replacement fitment and consistent performance. The Denso Air / Fuel Ratio Sensor - OE Style line is focused on direct-fit service parts for vehicles that require OE-style sensor response and installation geometry.