Walker 350-34025 Oxygen Sensor - Upstream, Upstream Left or Upstream Right

Walker 350-34025 Oxygen Sensor for BMW Upstream Applications

Walker Products 350-34025 is a heated oxygen sensor built for specific upstream BMW applications. It is engineered as an OE-style replacement to deliver the diagnostic feedback the ECU expects, helping maintain proper fuel control and emissions performance.

Key Features

• Heated oxygen sensor with 4-wire design
• Specific fit for targeted BMW upstream locations
• Threaded mounting with 18.0 mm thread diameter
• Female connector with radiused polygon shape
• Wiring harness length: 10.55 in; overall length: 14.09 in
• Wire gauge: 20

Product Details

Walker Products Aftermarket focuses on engine management and oxygen/air-fuel sensors engineered for OE replacement use. Part number 350-34025 is designed for the correct application and fitment position, making it a direct choice for BMW 325i, 325is, M3, 530i, 540i, 740i, and 740iL upstream sensor service where listed. This sensor supports ECU feedback on vehicles that store fault codes when the oxygen sensor circuit or related systems are affected.

Walker 350-34025 is a practical replacement when the original sensor has aged, wiring has been damaged, or the connector has degraded. This part cross-references no listed interchange numbers in the provided data.

Vehicle Fitment

• Fits 1992-1995 BMW 325i, upstream.
• Fits 1992-1995 BMW 325is, upstream.
• Fits 1995 BMW M3, upstream for cylinders 1-3.
• Fits 1995 BMW M3, upstream for cylinders 4-6.
• Fits 1994 BMW 530i, upstream right, to 06/1994.
• Fits 1994 BMW 530i, upstream left, to 06/1994.
• Fits 1994 BMW 530i, upstream right.
• Fits 1994 BMW 530i, upstream left.
• Fits 1994 BMW 540i, upstream right, to 3/94.
• Fits 1994 BMW 540i, upstream left, to 3/94.
• Fits 1994 BMW 540i, upstream right.
• Fits 1994 BMW 540i, upstream left.
• Fits 1993-1994 BMW 740i, upstream right.
• Fits 1993-1994 BMW 740i, upstream left.
• Fits 1993-1994 BMW 740iL, upstream right.
• Fits 1993-1994 BMW 740iL, upstream left.

Common Issues This Sensor Can Address

• Check engine light related to oxygen sensor performance
• Rough engine operation caused by incorrect air-fuel feedback
• Increased fuel consumption from inaccurate sensor readings
• Higher exhaust emissions from a failing upstream sensor
• Fault codes stored in the ECU for sensor or related circuit issues

Installation Notes

Confirm the vehicle’s exact year, model, and sensor position before ordering. For best results, inspect the sensor wiring harness and connector for physical damage before installation, since damaged wiring can shorten sensor life and affect operation. Verify the threaded mounting location and connector style match the original part on your BMW 325i, 325is, M3, 530i, 540i, 740i, or 740iL.

Quality Assurance

Walker Products has manufactured engine management components since 1946 and operates as an Automotive ISO9001/TS 16949 certified company. The 350-34025 is built as a specific-fit replacement oxygen sensor for the listed BMW upstream applications.