NTK 21065 Oxygen Sensor - Downstream Left or Downstream Right

NTK Direct Fit Oxygen Sensor 21065

NTK Direct Fit Oxygen Sensor 21065 is a heated, threaded oxygen sensor built for specific-fit replacement in select GM trucks and SUV applications. It is engineered for the downstream left and downstream right positions on 2008-2013 Chevrolet Silverado 1500, 2008-2013 GMC Sierra 1500, and 2008 Hummer H2 applications.

As part of NTK’s Direct Fit Oxygen Sensor line, this sensor is built around OE-style fit, form, and function. NTK applies ceramic manufacturing expertise and extensive production testing to support consistent signal performance and reliable emissions-system operation.

Key Features

• Specific-fit oxygen sensor for direct replacement service
• Heated sensor design for faster operating temperature
• 4-wire configuration with 15.0000 wiring harness length
• Threaded mounting with 18.000 thread diameter
• Compatible with downstream left and downstream right locations
• OE-style replacement for Chevrolet Silverado 1500, GMC Sierra 1500, and Hummer H2 applications

Product Details

NTK 21065 is a direct fit oxygen sensor intended for emissions control service where accurate exhaust feedback is required. It is built for specific vehicle applications rather than universal use, which helps support proper connector match, mounting, and sensor placement. This part cross-references DENSO Auto Parts 234-4258 for the same application.

For 2008-2013 Chevrolet Silverado 1500 and 2008-2013 GMC Sierra 1500, this sensor is listed for downstream left and downstream right positions. It is also listed for 2008 Hummer H2 in downstream left and downstream right positions. If you are searching for an oxygen sensor for Chevrolet Silverado 1500 downstream right, GMC Sierra 1500 downstream left, or Hummer H2 downstream oxygen sensor service, NTK 21065 is the direct-fit option to review.

Common Issues This Part May Address

• Check engine light related to oxygen sensor performance
• Faulty downstream sensor readings affecting emissions monitoring
• Rough or inconsistent fuel control caused by inaccurate exhaust feedback
• Failed sensor response from heat-related wear
• Replacement needs after diagnostic trouble codes point to the downstream O2 sensor

Installation Notes and Tips

Confirm the vehicle’s year, make, model, and sensor position before ordering. This sensor uses a threaded mounting style and a 4-wire heated design, so verify connector routing and harness length against the original part. For best results, compare the old sensor’s location and wiring path before installation on Silverado 1500, Sierra 1500, or Hummer H2 applications.

Quality Assurance

NTK is a major original equipment oxygen sensor manufacturer with extensive OE application coverage. Each sensor is manufactured and tested to meet or exceed OE specifications for fit and reliability. Part number 21065 is part of NTK’s Direct Fit Oxygen Sensor line, which is focused on accurate replacement for import and domestic vehicles.