Walker 250-25161 Oxygen Sensor - Upstream or Upstream Right

Walker OE Base Oxygen Sensor

Walker OE Base Sensor 250-25161 is a specific-fit, heated wide-band oxygen sensor for vehicles that need accurate exhaust feedback to the ECU. It is built for direct application use on select Cadillac XLR and Subaru models, including upstream right and upstream B1S1 positions.

Key Features

• Heated wide-band oxygen sensor for precise air-fuel monitoring
• Specific-fit design for the listed vehicle applications
• 5-wire construction with 6 terminals
• Rectangle female connector with male terminals
• M18 x 1.5 thread size and 22 mm wrench size
• Walker OE Base Sensor line for OE-style replacement applications

Product Details

Walker Products 250-25161 is engineered as an OE replacement oxygen sensor for select 2004-2005 Cadillac XLR and 2000-2002 Subaru Forester, Impreza, Legacy, and Outback applications. This wide-band sensor is positioned upstream to provide the ECU with the exhaust data needed for fuel control and emissions management. The OE Base Sensor line focuses on application-specific fitment, making it a direct-match option for vehicles that require the correct sensor length, connector style, and diagnostic feedback.

This part number 250-25161 is used where the original sensor has a heated wide-band design and a specific connector and terminal layout. Walker Products has supplied engine management and oxygen/air-fuel sensors since 1946 and manufactures electronic components under ISO 9001/TS 16949 quality systems.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Poor fuel economy caused by incorrect air-fuel feedback
• Rough engine operation from inaccurate exhaust readings
• Increased exhaust emissions from a failing upstream sensor
• Fault codes stored in the ECU for sensor or related system issues

Installation Notes

Before replacement, inspect the sensor wiring harness and connector for damage, since physical wear can shorten sensor life and affect operation. Confirm the upstream right or upstream B1S1 location, thread size, and connector style against the original part before installation. For 2005 Cadillac XLR, verify the 1st design sensor length noted in the fitment data.

Quality Assurance

Walker Products manufactures this OE Base Sensor as an application-specific replacement part for the listed vehicles. The brand’s engine management components are produced under ISO 9001/TS 16949 certified quality systems, with fitment and diagnostic feedback aligned to the original vehicle requirements.