Walker 350-64005 Oxygen Sensor - Upstream

Walker 350-64005 Oxygen Sensor Overview

Walker Products 350-64005 is a heated, specific-fit oxygen sensor engineered as an OE-style replacement for select Subaru and Saab applications. It is built for upstream placement and provides the ECU with the feedback needed to monitor air-fuel control on the affected engine management system.

For Subaru Impreza, Forester, Legacy, and Outback models, as well as the Saab 9-2X, this upstream oxygen sensor is matched to the listed application and connector style for direct replacement service.

Key Features

• Heated oxygen sensor for upstream engine management feedback
• Specific-fit design for listed Subaru and Saab applications
• 4-wire configuration with female connector
• Threaded mounting type with 18.0 mm thread diameter
• Wiring harness length: 20.2
• Overall length: 23.74
• Radiused polygon connector shape for application-specific fitment
• Walker Products Aftermarket part number 350-64005

Detailed Description

Walker Products Aftermarket 350-64005 is an oxygen sensor designed for upstream installation where the ECU relies on accurate exhaust feedback to manage fuel delivery and emissions. This part is listed for 2004-2011 Subaru Impreza, Forester, Legacy, and Outback applications, plus the 2006 Saab 9-2X, with fitment notes identifying Bank 1 Sensor 1 and front oxygen sensor positions where applicable. If you are replacing a failing upstream oxygen sensor on a Subaru Legacy or Subaru Outback, this part number is built around the listed vehicle-specific configuration rather than a universal layout.

Walker Products has long focused on engine management and oxygen/air-fuel sensors for OE-style replacement use. Part number 350-64005 follows that approach with application-specific fitment, threaded mounting, and the connector and harness details needed for the listed vehicles.

What It Helps Address

• Check engine light related to upstream oxygen sensor faults
• Poor engine performance caused by incorrect air-fuel feedback
• Increased fuel consumption from inaccurate exhaust sensing
• Higher exhaust emissions from a degraded sensor signal
• Stored ECU fault codes tied to Bank 1 Sensor 1 or front sensor positions

Installation Notes and Tips

Confirm the vehicle year, make, model, and sensor position before ordering. This part is listed for upstream use only, so match it to the correct Bank 1 Sensor 1 or front oxygen sensor location shown in the fitment data. Before installation, inspect the sensor wiring harness and connector for heat damage, abrasion, or corrosion, since damaged wiring can shorten sensor life and affect ECU feedback. Verify the thread diameter and connector style against the original sensor before replacement.

Quality Assurance

Walker Products manufactures engine management sensors under ISO 9001 and TS 16949 quality systems. The brand states that its oxygen and air-fuel sensors are developed as OE replacement parts for specific applications, with fitment and diagnostic feedback matched to the vehicle’s ECU requirements.

• Fits 2006-2011 Subaru Impreza, upstream
• Fits 2006-2010 Subaru Forester, upstream
• Fits 2006-2009 Subaru Legacy, upstream
• Fits 2004 Subaru Legacy, upstream
• Fits 2006-2009 Subaru Outback, upstream
• Fits 2005 Subaru Outback, upstream
• Fits 2004 Subaru Outback, upstream
• Fits 2006 Saab 9-2X, upstream