Walker 350-31001 Oxygen Sensor - Upstream

Walker 350-31001 Oxygen Sensor Overview

Walker Products 350-31001 is a specific-fit oxygen sensor engineered for selected Mazda applications with upstream placement. It is built to provide the ECU with the feedback needed for fuel control and emissions monitoring, making it a direct replacement choice for vehicles that rely on accurate exhaust oxygen readings.

Compatible with 1990-1992 Mazda MX-6 upstream oxygen sensor applications and 1990-1991 Mazda 626 turbo upstream oxygen sensor applications, this Walker Products Aftermarket sensor is designed around the original application, connector style, and threaded mounting requirements.

Key Features

• Part number: 350-31001
• Specific-fit oxygen sensor for targeted Mazda applications
• Upstream sensor position for bank 1 sensor 1 applications where listed
• Non-heated sensor design
• Threaded mounting type with 18.0 mm thread diameter
• Radiused polygon male connector
• 15.28 in. wiring harness length
• 20-gauge, 1-wire configuration
• Overall length: 18.82 in.

Walker Products Aftermarket Line

Walker Products Aftermarket focuses on engine management and oxygen/air-fuel sensor replacements built for application-specific fitment. The line is aimed at restoring the diagnostic feedback the ECU expects, which is important on vehicles that store fault codes when sensor performance drops outside normal range.

Detailed Description

The Walker 350-31001 oxygen sensor is an OE-style replacement for selected Mazda vehicles that use an upstream, threaded sensor location. It is intended for 1990-1992 Mazda MX-6 upstream oxygen sensor service and 1990-1991 Mazda 626 turbo upstream oxygen sensor service, including Bank 1 Sensor 1 applications noted in the fitment data. If your Mazda MX-6 or Mazda 626 is showing fuel trim issues, emissions concerns, or a malfunction indicator light tied to oxygen sensor performance, this part number is built for that exact service position.

Walker Products has long focused on engine management sensors, and this part reflects that application-specific approach. The 350-31001 uses a non-heated design, a male radiused polygon connector, and a threaded mount to match the original sensor interface on the listed vehicles.

What It Helps Address

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

Installation Notes

Before installation, inspect the sensor wiring harness and connector for heat damage, corrosion, or broken terminals. Confirm the vehicle uses the listed upstream application and threaded 18.0 mm sensor location before ordering. For Mazda MX-6 and Mazda 626 service, verify the connector shape and wire configuration match the original part to ensure proper ECU feedback after replacement.

This part cross-references Walker Products Aftermarket 350-31001 for the same application.

Quality Assurance

Walker Products states that its engine management sensors are manufactured for specific applications and fitment positions, with production supported by Automotive ISO9001/TS 16949 certification. The brand has supplied engine management and fuel system components since 1946, with a focus on consistent diagnostic performance for the listed Mazda applications.