Walker 350-34259 Oxygen Sensor - Upstream, Upstream Left or Upstream Right

Walker 350-34259 Oxygen Sensor Overview

Walker Products 350-34259 is a heated oxygen sensor built as a specific-fit OE replacement for select Chevrolet and GMC trucks, vans, and SUVs. It is engineered to deliver the diagnostic feedback the ECU expects, helping maintain proper fuel control and emissions performance.

Walker Products Aftermarket focuses on engine management and oxygen/air-fuel sensors for application-specific fitment. The 350-34259 follows that approach with the correct mounting style, connector layout, and sensor configuration for the listed upstream positions.

Key Features

• Heated oxygen sensor for faster operating response
• Specific-fit design for direct application matching
• 4-wire configuration with male connector
• Threaded mounting with 18.0 mm thread diameter
• Wiring harness length: 12.32 in.; overall length: 15.87 in.
• Radiused polygon connector shape for vehicle-specific connection

Detailed Description

This Walker oxygen sensor, part number 350-34259, is designed for upstream placement on a wide range of GM full-size trucks, vans, and SUVs. It is a direct replacement for vehicles such as the Chevrolet Express 2500, Chevrolet Express 3500, GMC Savana 2500, GMC Savana 3500, and related Chevrolet and GMC applications listed below. For buyers searching for an upstream oxygen sensor for a 1996-2002 Chevrolet Express 2500 or a 1997-2002 GMC Savana 2500, this part number provides the correct application-specific configuration.

As an OE-style replacement sensor, it is intended to restore accurate exhaust-gas feedback to the ECU. When an oxygen sensor begins to fail, common results include poor engine operation, higher fuel consumption, increased exhaust emissions, and a malfunction indicator light. Checking the sensor, wiring harness, and connector for damage is important because physical wear can shorten service life.

This part cross-references Walker Products Aftermarket 350-34259 for the same application.

What It Can Help Address

• Illuminated MIL or check engine light related to oxygen sensor performance
• Rough running or inconsistent engine response
• Excess fuel consumption caused by inaccurate exhaust feedback
• Elevated exhaust emissions from a faulty upstream sensor
• Diagnostic trouble codes stored in the ECU for sensor-related faults

Installation Notes and Fitment

• Fits 1996-2002 Chevrolet Express 2500, upstream right.
• Fits 1996-2002 Chevrolet Express 2500, upstream left.
• Fits 1996-2002 Chevrolet Express 3500, upstream right.
• Fits 1996-2002 Chevrolet Express 3500, upstream left.
• Fits 1997-2002 GMC Savana 2500, upstream right.
• Fits 1997-2002 GMC Savana 2500, upstream left.
• Fits 1997-2002 GMC Savana 3500, upstream right.
• Fits 1997-2002 GMC Savana 3500, upstream left.
• Fits 1996-2000 Chevrolet C2500, upstream right and upstream left.
• Fits 1996-2000 GMC K3500, upstream right and upstream left.
• Fits 1996-1999 Chevrolet Tahoe, upstream.

Confirm the vehicle’s upstream sensor position, connector style, and thread size before installation. Inspect the harness and connector for heat damage or corrosion, and verify the ECU fault code before replacing the sensor. This part is used on Chevrolet and GMC applications including Express, Savana, C/K-series, Tahoe, Yukon, and related models listed in the fitment data.

Quality Assurance

Walker Products states that its engine management and oxygen sensor lines are developed as OE replacement parts and manufactured under Automotive ISO9001/TS 16949 certification standards. The brand has supplied engine management components since 1946, with application-specific cataloging for modern vehicle fitment.