Walker 250-54079 Oxygen Sensor - Upstream

OE Oxygen Sensor for Subaru Impreza and WRX STI

Walker Products OE 250-54079 is a heated, specific-fit oxygen sensor engineered for direct replacement in select Subaru applications. It is built for upstream placement and provides the ECU with the feedback needed for accurate fuel control and emissions monitoring.

Key Features

• Heated oxygen sensor for faster operating response
• Specific fit for the listed Subaru applications
• Upstream mounting position
• 4-wire design with 20-gauge wiring
• Threaded mount with 18.0 mm thread diameter
• Radiused polygon male connector for vehicle-specific connection
• Wiring harness length: 29.06 in.; overall length: 32.6 in.

Product Details

Walker Products OE 250-54079 is part of the Walker Products OE line, which focuses on original-equipment-style replacement sensors for vehicle-specific fitment and ECU feedback requirements. This oxygen sensor is listed for 2008-2014 Subaru Impreza, upstream, and 2014 Subaru WRX STI, upstream. It is designed for Bank 1 Sensor 1 and front oxygen sensor applications where the vehicle calls for an upstream heated oxygen sensor. The part number 250-54079 is a direct reference for shoppers searching for an upstream oxygen sensor for Subaru Impreza or Subaru WRX STI models.

This part cross-references Walker Products OE 250-54079 for the same application.

Common Issues This Sensor Can Address

• Check engine light or malfunction indicator light related to oxygen sensor performance
• Poor engine operation caused by incorrect air-fuel feedback
• Increased fuel consumption from inaccurate exhaust readings
• Higher exhaust emissions from a failing upstream sensor
• Stored ECU fault codes tied to the affected sensor circuit

Installation Notes and Tips

Verify the connector shape, wire count, thread diameter, and upstream position before installation. Inspect the sensor wiring harness and connector for heat damage, abrasion, or corrosion, since physical damage can shorten service life and affect signal quality. Confirm the vehicle’s fault code and sensor location before replacing the part. For Subaru Impreza and WRX STI applications, match the upstream Bank 1 Sensor 1 or front oxygen sensor requirement exactly.

Quality Assurance

Walker Products has produced engine management and oxygen sensor components since 1946 and manufactures this part as an OE-style replacement for the specified application. The company is ISO 9001/TS 16949 certified, supporting consistent manufacturing and application-specific fitment.