Walker 350-34154 Oxygen Sensor - Upstream or Upstream Rear

Walker 350-34154 Oxygen Sensor for Mazda

Walker Products 350-34154 is a heated oxygen sensor built as a specific-fit OE-style replacement for select Mazda applications. It is designed for upstream and upstream rear positions where accurate exhaust feedback is needed for engine management on Mazda 6 and Mazda Millenia models.

Key Features

• Heated oxygen sensor for faster operating response
• Specific fitment for the listed Mazda applications
• Threaded mounting design with 18.0 mm thread diameter
• 4-wire configuration with 20-gauge wiring
• Radiused polygon male connector for application-specific connection
• Wiring harness length: 21.97 in.; overall length: 25.51 in.

Product Details

The Walker Products Aftermarket line focuses on engine management and oxygen/air-fuel sensors engineered for OE replacement use. Part number 350-34154 is built for the correct fitment position and ECU feedback requirements on the listed vehicles, helping maintain proper sensor input for fuel control and emissions monitoring. This part cross-references standard oxygen sensor applications where the same OE-style fitment is required.

Fits 2003-2005 Mazda 6, upstream. Fits 2005 Mazda 6, upstream for non-California emissions vehicles and Bank 1 Sensor 1 applications. Fits 2001-2002 Mazda Millenia, upstream rear.

What It Helps Address

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

Installation Notes

Confirm the vehicle’s emissions calibration, sensor position, connector style, and thread size before installation. For 2005 Mazda 6 applications, verify that the vehicle is not California emissions certified, as this sensor is not listed for California-ESV vehicles. Inspect the sensor wiring harness and connector for damage before replacement, since damaged wiring can shorten sensor life and affect readings.

Quality Assurance

Walker Products has supplied engine management components since 1946 and manufactures this sensor as a specific-application replacement for the listed Mazda fitments. The company is ISO 9001/TS 16949 certified, supporting consistent production and application matching.