Walker 350-34030 Oxygen Sensor - Upstream

Walker 350-34030 Oxygen Sensor for BMW Upstream Fitment

Walker Products 350-34030 is a heated oxygen sensor built as a specific-fit OE-style replacement for select BMW applications. It is engineered for upstream placement and provides the ECU with the feedback needed for fuel control and emissions monitoring.

Key Features

• Heated oxygen sensor for faster operating response
• Specific-fit design for the listed BMW applications
• Upstream mounting position
• 4-wire configuration with 20-gauge wiring
• Threaded mount with 18.0 mm thread diameter
• Radiused polygon male connector for vehicle-specific connection
• Wiring harness length: 21.77 in.; overall length: 25.31 in.

Product Details

Walker Products Aftermarket focuses on engine management and oxygen/air-fuel sensors engineered for OE replacement use. Part number 350-34030 is built for the specified fitment and upstream location, making it a direct-match oxygen sensor for 1987-1988 BMW 325is, 1988 BMW 325i, 1988 BMW 325iX, and 1988 BMW 528e applications listed below. This sensor supports the diagnostic feedback the ECU relies on to manage air-fuel ratio and emissions performance.

This part cross-references no listed interchange numbers in the provided data. For BMW 325i upstream oxygen sensor replacement, BMW 325is upstream oxygen sensor replacement, or BMW 528e upstream oxygen sensor service, 350-34030 is the referenced Walker Products part number.

Common Issues This Sensor May Address

• Check engine light or malfunction indicator light related to oxygen sensor performance
• Poor engine operation caused by incorrect exhaust feedback
• Increased fuel consumption from inaccurate air-fuel control
• Higher exhaust emissions from a failing upstream sensor
• Stored ECU fault codes tied to the affected sensor circuit

Installation Notes and Tips

Confirm the vehicle is one of the listed upstream BMW applications before ordering. Inspect the sensor wiring harness and connector for damage during diagnosis, since physical wear can shorten service life and affect signal quality. Verify threaded mounting dimensions and connector style match the original sensor location before installation.

Quality Assurance

Walker Products states that its engine management sensors are developed as OE replacement parts and manufactured under Automotive ISO 9001/TS 16949 quality systems. Since 1946, Walker Products has supplied engine management and fuel system components for vehicle service applications.