Walker 350-34584 Oxygen Sensor - Upstream, Upstream Left or Upstream Right

Walker 350-34584 Oxygen Sensor Overview

Walker Products 350-34584 is a heated, specific-fit oxygen sensor engineered as an OE-style replacement for select BMW applications. It is built for the correct mounting position and ECU feedback requirements, helping restore accurate exhaust monitoring on covered BMW 325i, 325is, 325iX, and 850CSi models.

Walker Products Aftermarket focuses on application-specific engine management sensors, and this part follows that approach with the proper threaded mount, 4-wire heated design, and female connector configuration for the listed vehicles.

Key Features

• Part number: 350-34584
• Heated oxygen sensor for faster operating response
• Specific fit for the listed BMW applications
• 4-wire design with 20-gauge wiring
• Female connector with radiused polygon shape
• Threaded mounting type with 18.0 mm thread diameter
• Wiring harness length: 22.36
• Overall length: 25.91

Vehicle Fitment

• Fits 1994-1995 BMW 850CSi, Upstream Right.
• Fits 1994-1995 BMW 850CSi, Upstream Left.
• Fits 1987 BMW 325i, Upstream.
• Fits 1988 BMW 325i, Upstream.
• Fits 1989-1991 BMW 325i, Upstream.
• Fits 1988 BMW 325is, Upstream.
• Fits 1989-1991 BMW 325is, Upstream.
• Fits 1988 BMW 325iX, Upstream.
• Fits 1989-1991 BMW 325iX, Upstream.

What This Sensor Helps Address

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

Installation Notes and Tips

Use the vehicle’s original sensor location and confirm upstream placement before installation. Inspect the sensor wiring harness and connector for heat damage, abrasion, or corrosion, since physical damage can shorten service life and affect signal quality. Verify thread size, connector style, and harness routing against the removed part before final installation.

For BMW 325i oxygen sensor replacement, BMW 325is upstream sensor service, or BMW 850CSi upstream left/right oxygen sensor replacement, confirm the listed position and model year before ordering. Part number 350-34584 is a direct-fit style solution for the specified applications.

Quality Assurance

Walker Products has supplied engine management and fuel system components since 1946 and operates as an Automotive ISO9001/TS 16949 certified company. The Walker Products Aftermarket line is built around application-specific replacement parts for modern diagnostic systems, including oxygen sensors that provide the ECU with the expected feedback for the covered vehicles.