Walker 350-34031 Oxygen Sensor - Upstream

Walker 350-34031 Oxygen Sensor Overview

Walker Products 350-34031 is a heated oxygen sensor built as a specific-fit OE replacement for select Nissan applications. It is engineered for upstream placement and uses a 4-wire, threaded design to deliver the feedback the ECU relies on for fuel control and emissions monitoring.

Fits 1986-1989 Nissan D21, upstream. Fits 1987-1989 Nissan Pathfinder, upstream.

Key Features

• Heated oxygen sensor for faster operating response
• Specific-fit design for the listed Nissan applications
• Upstream sensor position for ECU feedback
• 4-wire configuration with 20-gauge wiring
• Radiused polygon male connector for vehicle-specific connection
• Threaded mounting with 12.0 mm thread diameter
• Wiring harness length: 68.03 in.; overall length: 71.57 in.

Detailed Description

Walker Products Aftermarket focuses on engine management and oxygen/air-fuel sensors engineered as OE-style replacements for a wide range of vehicles. Part number 350-34031 is built for the upstream oxygen sensor location on the 1986-1989 Nissan D21 and 1987-1989 Nissan Pathfinder, where it helps the ECU monitor exhaust oxygen content and adjust air-fuel delivery. If the original sensor is slow, damaged, or out of range, the vehicle can run rich or lean, trigger a malfunction indicator light, and increase emissions or fuel use. Walker 350-34031 is designed around the listed application, connector style, and mounting dimensions for a direct replacement approach.

This part cross-references no listed interchange numbers for the same application.

What It Helps Address

• Check engine or malfunction indicator light related to oxygen sensor performance
• Poor fuel economy caused by inaccurate exhaust feedback
• Rough running or inconsistent air-fuel control
• Higher exhaust emissions from a failing upstream sensor
• Fault codes stored in the ECU for sensor-related issues

Installation Notes and Tips

Confirm the upstream sensor location before installation on the Nissan D21 or Nissan Pathfinder. Inspect the sensor wiring harness and connector for heat damage, corrosion, or broken terminals before replacing the part. Verify thread size, connector shape, and harness length against the original sensor to ensure proper routing and fitment. Because this is a threaded sensor, clean the mounting area and remove any contamination that could affect sealing or signal accuracy.

Quality Assurance

Walker Products has manufactured engine management components since 1946 and operates with Automotive ISO9001/TS 16949 certification. The 350-34031 is produced as a specific application replacement to support the diagnostic feedback expected by the vehicle ECU.