Walker 350-35021 Oxygen Sensor - Upstream

Walker 350-35021 Oxygen Sensor Overview

Walker Products 350-35021 is a heated oxygen sensor built as a specific-fit OE replacement for select Mazda applications. It is engineered to provide the ECU with the exhaust feedback needed for fuel control and emissions monitoring, making it a direct service part for upstream sensor replacement on covered vehicles.

Compatible with 2009-2013 Mazda 6 upstream applications, this Walker Products Aftermarket sensor is designed around the correct connector, wiring, and mounting details for the listed position. The 350-35021 is a practical choice when diagnosing a check engine light, poor fuel economy, or elevated emissions tied to oxygen sensor performance.

Key Features

• Heated oxygen sensor for faster operating response
• Specific-fit design for the listed Mazda 6 upstream position
• 5-wire configuration with female connector
• Threaded mounting with 18.0 mm thread diameter
• 19.21 in. wiring harness length and 22.76 in. overall length
• Radiused polygon connector shape for application-specific fitment
• Walker Products Aftermarket part number 350-35021

Application Details

Walker Products develops engine management and oxygen/air-fuel sensors as OE-style replacement parts for many vehicles worldwide. Part number 350-35021 is built for the specific application and sensor location required by the vehicle ECU, helping maintain the diagnostic feedback expected from the upstream oxygen sensor on 2009-2013 Mazda 6 models. If you are replacing a front oxygen sensor on a Mazda 6, this part number 350-35021 is the listed upstream solution.

What It Helps Address

• Check engine light related to upstream oxygen sensor faults
• Poor fuel economy caused by incorrect exhaust feedback
• Rough engine operation from inaccurate air-fuel correction
• Higher exhaust emissions from a failing sensor
• Damaged sensor wiring or connector issues at the original location

Installation Notes

Confirm the vehicle is a 2009-2013 Mazda 6 with an upstream oxygen sensor requirement before ordering. Inspect the sensor harness, connector, and surrounding wiring for physical damage during replacement, since damaged components can shorten service life and affect ECU readings. The threaded design and application-specific connector help support a direct replacement process for the listed position.

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 350-35021 is manufactured for the specified fitment and diagnostic feedback requirements of the application.