Walker 350-34138 Oxygen Sensor

Walker 350-34138 Oxygen Sensor for Audi and Volkswagen

Walker Products 350-34138 is a heated oxygen sensor built as a specific-fit OE replacement for select Audi and Volkswagen applications. It is engineered to deliver the diagnostic feedback the ECU expects, helping maintain proper fuel control and emissions performance.

Key Features

• Heated oxygen sensor for downstream exhaust monitoring
• Specific fitment for the listed Audi A4, A6, A8, Allroad Quattro, RS4, RS6, S4, S6, S8, and Volkswagen Passat applications
• Threaded mounting design with 18.0 mm thread diameter
• 4-wire configuration with 22-gauge wiring
• Wiring harness length: 64.09 in; overall length: 67.64 in
• Radiused polygon connector with male terminal end

Product Details

Walker Products Aftermarket focuses on engine management and oxygen/air-fuel sensors built for application-specific replacement use. Part number 350-34138 is designed for downstream positions on select 2000-2005 Volkswagen Passat and 2000-2004 Audi A6 Quattro, along with other listed Audi performance and luxury models. If you are replacing a downstream rear, downstream front, downstream left, or downstream right sensor on an Audi A4, A4 Quattro, A6, A6 Quattro, A8 Quattro, Allroad Quattro, RS4, RS6, S4, S6, or S8, this sensor is matched to the vehicle position and ECU feedback requirements.

This part cross-references Bosch 15717 and Denso 234-9005 for the same application.

Common Issues This Sensor May Address

• Check engine light or malfunction indicator light related to oxygen sensor performance
• Poor fuel economy caused by inaccurate exhaust feedback
• Rough engine operation from incorrect air-fuel correction
• Elevated exhaust emissions from a failing downstream sensor
• Stored ECU fault codes tied to the affected sensor circuit

Installation Notes and Tips

• Confirm the exact downstream position before installation: rear, front, left, or right as listed for the vehicle.
• Inspect the sensor wiring harness and connector for heat damage, abrasion, or corrosion before replacement.
• Verify the threaded mounting point is clean and undamaged to ensure proper sensor seating.
• Use the vehicle’s ECU fault codes and service information to confirm the failed sensor location.

Quality Assurance

Walker Products has manufactured engine management components since 1946 and operates with Automotive ISO9001/TS 16949 certification. The 350-34138 oxygen sensor is built as a specific replacement for the listed Audi and Volkswagen applications, including 2000-2005 Volkswagen Passat and 2000-2004 Audi A6 Quattro coverage.