Walker 350-34057 Oxygen Sensor - Downstream

Walker 350-34057 Oxygen Sensor Overview

Walker Products 350-34057 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 choice for downstream sensor replacement on covered vehicles.

Compatible With 2004-2011 Mazda RX-8, downstream, and 1996-1998 Mazda MPV, downstream. The Walker Products Aftermarket line focuses on application-specific engine management sensors, and this part number follows that approach with vehicle-matched fitment and connector design.

Key Features

• Heated oxygen sensor for downstream placement
• Specific fit for the listed Mazda applications
• 4-wire design with male connector
• Threaded mounting type with 18.0 mm thread diameter
• Wiring harness length: 15.28 in.
• Overall length: 18.82 in.
• Radiused polygon connector shape for application-specific connection

Detailed Description

The Walker 350-34057 oxygen sensor is designed for exhaust monitoring after the catalytic converter on supported Mazda vehicles. On 2004-2011 Mazda RX-8 models, it serves as the downstream sensor, including bank 1 sensor 2 on specific vehicle configurations. It also covers 1996-1998 Mazda MPV downstream applications. If you are replacing a failing Mazda RX-8 oxygen sensor or sourcing a downstream oxygen sensor for a Mazda MPV, this part number provides the correct fitment profile for those vehicles.

Walker Products develops engine management and oxygen/air-fuel sensors as OE-style replacements for many global vehicle platforms. Part number 350-34057 is built for the specified application, fitment position, and ECU feedback requirements, helping maintain proper exhaust monitoring on the covered Mazda models.

This part cross-references no listed alternate part numbers in the provided data.

Common Issues This Sensor May Address

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

Installation Notes and Tips

Confirm the vehicle year, model, and sensor position before ordering. For 2004-2011 Mazda RX-8, verify the downstream location and bank 1 sensor 2 application where applicable. Inspect the sensor wiring harness and connector for heat damage, corrosion, or abrasion before installation, since physical damage can shorten sensor life. Threaded mounting requires proper removal and installation practices to avoid damaging the exhaust bung.

Quality Assurance

Walker Products is an automotive ISO 9001/TS 16949 certified company with a long history in engine management and fuel system components. The 350-34057 is manufactured for the specified application and position to deliver the diagnostic feedback expected by the vehicle ECU.