NTK 21063 Oxygen Sensor - Downstream

Direct Fit Oxygen Sensor for Hummer H3

NTK 21063 is a direct fit heated oxygen sensor built for specific applications, including the 2006 Hummer H3 downstream position. It is engineered to match OE-style fit, form, and function for accurate exhaust monitoring in the vehicle’s emission control system.

The NTK Direct Fit Oxygen Sensor line focuses on application-specific coverage and sensor technology for import and domestic vehicles. NTK 21063 follows that approach with a threaded mounting design, 4-wire configuration, and a 9-inch wiring harness length for a direct replacement on the listed Hummer H3 application.

Key Features

• Direct fit oxygen sensor for specific vehicle applications
• Heated sensor design for faster operating response
• 4-wire configuration
• Threaded mounting type with 18 mm thread diameter
• 9-inch wiring harness length
• OE-style fit, form, and function for emission control service

Product Details

NTK 21063 is an oxygen sensor for the 2006 Hummer H3, downstream position. It is built to meet OEM standards for the listed application and is manufactured with NTK’s ceramic sensor expertise, from raw material control through finished product. This part cross-references Bosch 15159 for the same application. If you are replacing a downstream oxygen sensor on a 2006 Hummer H3, NTK 21063 provides a direct replacement path without universal-fit adaptation.

Common Issues This Sensor Can Address

• Check engine light related to downstream oxygen sensor performance
• Fault codes tied to exhaust oxygen monitoring
• Incorrect air-fuel feedback from a worn sensor
• Emissions test failures caused by sensor degradation
• Rough or inconsistent engine management data from an aging sensor

Installation Notes

Verify the downstream sensor location before installation on the 2006 Hummer H3. Confirm the 18 mm threaded mounting point, 4-wire connector layout, and harness length match the original sensor routing. Inspect the connector and exhaust threads before installation to ensure proper seating and electrical connection.

Quality Assurance

NTK manufactures oxygen sensors with extensive production testing to support quality and reliability that meets or exceeds OE specifications. As part of the NGK family of products, NTK is a major OE oxygen sensor supplier with application coverage for import and domestic vehicles.