Walker 350-34080 Oxygen Sensor - Downstream or Downstream Front

Walker 350-34080 Oxygen Sensor for Mazda

Walker Products 350-34080 is a heated oxygen sensor built as a specific-fit OE-style replacement for select Mazda applications. It is engineered to deliver the ECU feedback needed for downstream and downstream front sensor positions on covered vehicles, including Mazda Protege, Protege5, and MPV models.

Key Features

• Heated oxygen sensor for precise exhaust feedback
• Specific fitment for the listed Mazda applications
• 4-wire design with female connector
• Threaded mounting with 18.0 mm thread diameter
• Wiring harness length: 23.54 in.; overall length: 27.09 in.
• Radiused polygon connector shape for application-specific connection
• Walker Products Aftermarket line for engine management and oxygen/air-fuel sensor coverage

Product Details

The Walker Products Aftermarket line focuses on engine management sensors built for direct replacement use in defined vehicle positions. Part number 350-34080 is a heated oxygen sensor designed for downstream and downstream front locations, with fitment listed for 1999-2003 Mazda Protege, 2002-2003 Mazda Protege5, and 2000-2001 Mazda MPV California emissions applications. This sensor is intended to restore the diagnostic feedback the ECU expects from the affected exhaust position. If the original sensor has failed, the vehicle may run poorly, use more fuel, increase emissions, or trigger the malfunction indicator light. Walker 350-34080 is built for the specified application, so connector style, harness length, and threaded mounting are matched to the listed fitment.

Walker Products has supplied engine management and fuel system components since 1946 and manufactures to automotive ISO 9001/TS 16949 standards.

Common Issues This Sensor May Address

• Check engine light related to oxygen sensor performance
• Poor fuel economy caused by incorrect exhaust feedback
• Rough engine operation from inaccurate air-fuel monitoring
• Elevated exhaust emissions from a failing downstream sensor
• Stored ECU fault codes tied to the affected sensor circuit

Installation Notes and Tips

Confirm the vehicle’s exact year, model, and sensor position before ordering. This part fits downstream bank 1 sensor 2 on specific Mazda Protege and Protege5 models, and downstream front on 2000-2001 Mazda MPV California emissions vehicles. Inspect the sensor wiring harness and connector for damage before installation, since damaged wiring can shorten sensor life and affect operation. Verify the threaded mounting location and connector orientation match the original part before final tightening.

Quality Assurance

Walker Products manufactures this oxygen sensor as an OE replacement for the listed applications and builds it under ISO 9001/TS 16949 quality systems. Part number 350-34080 is designed for application-specific fitment and ECU feedback requirements on the covered Mazda vehicles.