Walker 250-25166 Oxygen Sensor - Center, Downstream or Upstream

OE Base Wide-Band Oxygen Sensor

Walker OE Base Sensor 250-25166 is a specific-fit heated wide-band oxygen sensor built for direct replacement in select BMW, Audi, Volkswagen, Kia, and Hyundai applications. It provides ECU feedback for air-fuel control and emissions monitoring, making it a practical choice when diagnosing drivability issues or replacing a failed upstream sensor.

The OE Base Sensor line from Walker Products focuses on application-specific fitment and sensor position, so the replacement matches the vehicle’s required diagnostic response. For vehicles such as the BMW X5, Volkswagen CC, and Audi TT Quattro, correct sensor output is important for maintaining fuel control and emissions performance.

• Heated wide-band oxygen sensor for precise air-fuel feedback
• Specific-fit design for the listed vehicle applications
• 5-wire construction with 6 terminals
• Female connector with oblong shape
• M18 x 1.5 thread size and 22 mm wrench size
• Fits upstream, center, and downstream positions depending on application

Vehicle Fitment

• Fits 2014-2017 BMW X5, Upstream; B1S1; OE Base Sensor
• Fits 2009-2011 BMW X5, Upstream; B1S1; OE Base Sensor
• Fits 2011-2017 Volkswagen CC, Upstream; B1S1; OE Base Sensor
• Fits 2014-2016 BMW 535d, Upstream; B1S1; OE Base Sensor
• Fits 2014-2016 BMW 535d xDrive, Upstream; B1S1; OE Base Sensor
• Fits 2014-2016 Kia Forte, Upstream; B1S1; OE Base Sensor
• Fits 2014-2016 Kia Forte Koup, Center; B1S1; OE Base Sensor
• Fits 2014-2016 Kia Forte5, Center; B1S1; OE Base Sensor
• Fits 2012-2016 Kia Soul, Upstream; B1S1; OE Base Sensor
• Fits 2012-2016 Volkswagen Eos, Upstream; B1S1; OE Base Sensor
• Fits 2010 Volkswagen Eos, Upstream; B1S1; OE Base Sensor
• Fits 2015 Audi Q7, Downstream; B1S1; OE Base Sensor
• Fits 2012-2015 Audi TT Quattro, Upstream; B1S1; OE Base Sensor
• Fits 2015 Audi TTS Quattro, Upstream; OE Base Sensor
• Fits 2012-2013 Audi TTS Quattro, Upstream; OE Base Sensor
• Fits 2013-2014 Audi Q7, Downstream; OE Base Sensor
• Fits 2013-2014 Hyundai Elantra Coupe, Upstream; B1S1; OE Base Sensor
• Fits 2013-2014 Hyundai Elantra GT, Upstream; B1S1; OE Base Sensor
• Fits 2013-2014 Volkswagen GTI, Upstream; B1S1; OE Base Sensor
• Fits 2011-2013 Audi A3, Upstream; B1S1; OE Base Sensor
• Fits 2011-2013 Audi A3 Quattro, Upstream; B1S1; OE Base Sensor
• Fits 2011-2013 Hyundai Elantra, Upstream; B1S1; OE Base Sensor
• Fits 2012-2013 Volkswagen Golf R, Upstream; B1S1; OE Base Sensor
• Fits 2009-2011 BMW 335d, Upstream; B1S1; OE Base Sensor

What It Helps Address

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

Installation Notes

Confirm the connector shape, wire count, terminal style, and sensor position before installation. Inspect the sensor wiring harness and connector for damage, since physical wear can shorten service life and affect signal quality. This part number is commonly searched as Walker 250-25166 for BMW X5, Audi Q7, Volkswagen GTI, and related OE Base Sensor applications.

Quality Assurance

Walker Products has been producing engine management and oxygen sensor components since 1946 and operates as an ISO 9001/TS 16949 certified company. The OE Base Sensor line is built around application-specific replacement fitment and ECU-relevant feedback for the listed vehicles. This part cross-references Bosch (e.g., 172286, 182286) for the same application.