NTK 21549 Oxygen Sensor

Direct Fit Oxygen Sensor for OE Replacement

NTK Oxygen Sensor 21549 is a direct fit, heated oxygen sensor built for specific applications that require OE-style fit, form, and function. It is engineered for import and domestic vehicles and is backed by NTK’s focus on sensor technology and ceramic manufacturing control.

Fits 2003-2006 Chevrolet Silverado 1500, upstream right; Fits 2003-2006 Chevrolet Silverado 1500, upstream left; Fits 2003-2006 GMC Sierra 1500, upstream right; Fits 2003-2006 GMC Sierra 1500, upstream left; Fits 2010-2015 Chevrolet Camaro, upstream right; Fits 2010-2015 Chevrolet Camaro, upstream left.

Key Features

• Heated oxygen sensor with specific fitment for direct replacement
• 4-wire design with 15.0000 wiring harness length
• Threaded mounting with 18.000 thread diameter
• OE-style sensor construction for accurate air/fuel ratio feedback
• Manufactured and tested to meet or exceed OE specifications
• Cross-references Bosch 15282 and Delphi ES20008 for the same application

Product Details

NTK Direct Fit Oxygen Sensor 21549 is part of the NTK sensor line, which focuses on original-equipment-level coverage and application-specific replacement parts. NTK controls ceramic production from raw material through finished sensor, helping maintain consistent sensor response and build quality. This part is used in vehicles such as the Chevrolet Silverado 1500, GMC Sierra 1500, and Chevrolet Camaro where precise upstream or downstream oxygen sensor performance is required.

As an OE-style replacement, this sensor is built for specific positions including upstream right, upstream left, downstream right, and downstream left across listed applications. The direct fit design supports straightforward replacement on vehicles that use a threaded, heated 4-wire oxygen sensor configuration.

Common Issues This Sensor Can Address

• Check engine light related to oxygen sensor circuit or response faults
• Incorrect air/fuel ratio readings from a worn upstream sensor
• Reduced fuel control accuracy caused by slow sensor switching
• Emissions test failures tied to aging oxygen sensor performance
• Driveability concerns linked to degraded exhaust feedback data

Installation Notes and Tips

Verify the exact position before installation, since this part is listed for multiple upstream and downstream locations across different vehicles. Confirm the connector style, thread diameter, and harness length against the original sensor before replacement. For best results, inspect the exhaust bung threads and wiring routing during installation on Chevrolet Silverado 1500, GMC Sierra 1500, and Chevrolet Camaro applications.

Quality Assurance

NTK states that its oxygen sensors are extensively tested during manufacturing to help ensure quality and reliability that meet or exceed OE specifications. The brand’s OE application focus and sensor specialization support consistent replacement performance for the listed fitments.