Walker 350-33032 Oxygen Sensor - Upstream

Walker 350-33032 Oxygen Sensor for BMW Upstream Applications

Walker Products 350-33032 is a heated oxygen sensor built for specific upstream BMW applications. It is engineered as an OE-style replacement to deliver the feedback the ECU uses to manage fuel control, emissions, and drivability.

Compatible With 1987-1988 BMW 535i, upstream; 1987 BMW 635CSi, upstream; 1988 BMW M5, upstream; and 1987-1988 BMW M6, upstream. This Walker Products Aftermarket oxygen sensor is also listed for BMW M6 cylinders 1-3 and cylinders 4-6 in upstream locations.

Key Features

• Part number: 350-33032
• Heated oxygen sensor for upstream placement
• Specific fit application for listed BMW models
• 3-wire design with 20-gauge wiring
• Radiused polygon male connector
• Threaded mounting with 18.0 mm thread diameter
• Wiring harness length: 66.85 in.
• Overall length: 70.39 in.

Product Details

Walker Products Aftermarket focuses on engine management and oxygen/air-fuel sensors built for direct replacement use. The 350-33032 is made for the specified upstream BMW applications and provides the sensor input the ECU relies on for air-fuel control. For BMW 535i, BMW 635CSi, BMW M5, and BMW M6 applications, correct sensor feedback is important for maintaining stable engine operation and emissions performance.

The 350-33032 part number is a practical choice when replacing a failed upstream oxygen sensor on these vehicles. Walker Products has long supplied engine management components for automotive applications, and this sensor follows the application-specific fitment approach needed for proper installation and system communication.

What It Helps Address

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

Installation Notes

Install only in the listed upstream position for the confirmed BMW applications. Before replacement, inspect the sensor wiring harness and connector for damage, since damaged wiring can shorten sensor life and affect operation. Verify the threaded mounting location, connector shape, and harness routing before installation to ensure proper fitment.

Because this is a specific-fit oxygen sensor, confirm the vehicle year, model, and upstream location before ordering. The 350-33032 is listed for 1987-1988 BMW 535i, 1987 BMW 635CSi, 1988 BMW M5, and 1987-1988 BMW M6 applications.

Quality Assurance

Walker Products is an automotive ISO 9001/TS 16949 certified company with a long history in engine management and sensor manufacturing. The 350-33032 is built as an OE replacement-style sensor for the listed BMW applications and is backed by Walker Products’ established manufacturing standards.