NTK 25648 Oxygen Sensor - Downstream or Upstream

Direct Fit Oxygen Sensor for Mini Cooper

NTK 25648 is a direct fit heated oxygen sensor built for specific applications on the 2002-2008 Mini Cooper. It is engineered for upstream and downstream positions, with OE-style fit, form, and function for emissions system service.

Key Features

• Direct fit oxygen sensor for specific Mini Cooper applications
• Heated sensor design for faster operating temperature
• 4-wire configuration with 24.5 in. wiring harness length
• Threaded mounting type with 18 mm thread diameter
• Built to meet or exceed OE specifications through manufacturing test validation
• Fits 2002-2008 Mini Cooper, upstream
• Fits 2002-2008 Mini Cooper, downstream

Product Details

NTK Direct Fit Oxygen Sensor 25648 is part of NTK’s OE-focused oxygen sensor line for import and domestic vehicles. NTK applies ceramic manufacturing expertise and production control from raw material through finished sensor, supporting consistent signal performance and proper integration with the vehicle’s emissions control system. For Mini Cooper oxygen sensor replacement, this part supports both Bank 1 Sensor 1 upstream service and B1S2 downstream service on the listed model years.

This part cross-references Delphi ES20222 for the same application.

Common Issues This Sensor Can Address

• Check engine light related to oxygen sensor circuit faults
• Incorrect air-fuel ratio readings from a worn sensor
• Reduced fuel economy caused by inaccurate exhaust feedback
• Emissions test failures tied to sensor response or heater circuit problems
• Rough idle or drivability concerns linked to aging O2 sensor data

Installation Notes and Tips

Verify the sensor position before installation: upstream Bank 1 Sensor 1 or downstream B1S2, depending on the repair location. Confirm the 18 mm threaded mounting point and 4-wire connector match the vehicle harness and exhaust bung. Inspect the connector routing and harness length during installation to avoid strain or heat damage.

Quality Assurance

NTK manufactures oxygen sensors with extensive testing during production to support reliability and OE-level performance. As a major supplier of original equipment oxygen sensors, NTK backs this direct fit design with application-specific engineering for the 2002-2008 Mini Cooper platform.