Walker 350-34392 Oxygen Sensor - Downstream

Walker 350-34392 Oxygen Sensor for Mazda

Walker Products 350-34392 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 feedback needed for proper fuel control and emissions monitoring, making it a direct replacement choice for downstream and upstream positions where listed.

Key Features

• Heated oxygen sensor for faster operating response
• Specific-fit design for the listed Mazda applications
• 4-wire configuration with 20-gauge wiring
• Threaded mounting with 18.0 mm thread diameter
• Radiused polygon male connector for vehicle-specific connection
• Overall length: 18.82 in.; wiring harness length: 15.28 in.

Product Details

Walker Products Aftermarket focuses on engine management and oxygen/air-fuel sensors engineered for OE-style replacement use. Part number 350-34392 is built for the specified fitment positions and is intended to restore accurate sensor feedback to the engine control unit. This matters on modern vehicles because the ECU can store fault codes tied to sensor performance, and a failing sensor can contribute to poor drivability, higher fuel use, increased exhaust emissions, or a malfunction indicator light. This part cross-references common OE-style replacement needs for the same application.

Compatible With Mazda 3, Mazda 3 Sport, and Mazda 5 applications listed below, this sensor is a direct-fit option for drivers servicing a downstream bank 1 sensor 2 location or the specified upstream position on select Mazda 3 Sport models. If you are searching for a Mazda 3 downstream oxygen sensor or a Mazda 5 downstream O2 sensor, Walker 350-34392 is the part number to verify against your vehicle.

What It Helps Address

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

Installation Notes

Verify the connector shape, wire count, thread diameter, and sensor position before installation. This part is specific fit, so confirm whether your vehicle uses the downstream bank 1 sensor 2 location or the listed upstream application. Inspect the sensor wiring harness and connector for heat damage, abrasion, or corrosion before replacement, since physical damage can shorten service life and affect operation.

• Fits 2012-2015 Mazda 5, downstream bank 1 sensor 2
• Fits 2011-2013 Mazda 3, downstream bank 1 sensor 2
• Fits 2012-2013 Mazda 3 Sport, downstream
• Fits 2011 Mazda 3 Sport, upstream, from 07/01/2010
• Fits 2010 Mazda 3 Sport, downstream, from 07/01/2010

Quality Assurance

Walker Products has been producing engine management and fuel system components since 1946 and operates under Automotive ISO 9001/TS 16949 certification. The 350-34392 oxygen sensor is manufactured for the specified application and fitment position to support the diagnostic feedback expected by the ECU.