NTK 21546 Oxygen Sensor

Direct Fit Oxygen Sensor for OE Replacement

NTK Oxygen Sensor 21546 is a direct fit, heated oxygen sensor built for specific vehicle applications that require OE-style fit, form, and function. It is engineered for import and domestic use and is a practical replacement for upstream and downstream positions across a wide range of GM vehicles, including Chevrolet Silverado 1500, GMC Sierra 1500, and Cadillac Escalade applications.

Key Features

• Heated oxygen sensor design for faster operating response
• Specific fit for direct replacement installation
• 4-wire configuration with 16.5 in. wiring harness length
• Threaded mounting type with 18 mm thread diameter
• Built to meet or exceed OE specifications through manufacturing test validation
• OE-style replacement for air/fuel ratio and emissions monitoring

Product Line Details

NTK Direct Fit Oxygen Sensor products are part of the NTK Sensor Specialist line, focused on OE application coverage and streamlined replacement options. NTK uses ceramic manufacturing expertise and controlled production processes to deliver sensors with consistent fit and function for modern emission control systems.

Detailed Description

Part number 21546 is designed for vehicles that use a heated, threaded oxygen sensor with a 4-wire layout and a 16.5-inch harness. It serves as a direct replacement for many upstream positions, including Bank 1 Sensor 1 applications, and also covers select downstream positions where listed. This part cross-references Bosch 15152 and DENSO Auto Parts 234-4342 for the same application. If you are replacing an oxygen sensor on a Chevrolet Silverado 1500, GMC Sierra 1500, or Cadillac CTS, this NTK sensor provides the OE-style configuration needed for proper emissions system service.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air/fuel ratio readings
• Emissions test failures tied to sensor response
• Rough idle or drivability issues caused by faulty sensor feedback
• Slow sensor warm-up in heated oxygen sensor circuits

Installation Notes and Fitment

Fits 2009-2015 Cadillac CTS, upstream right and upstream left. Fits 2008-2014 Cadillac Escalade, upstream right and upstream left. Fits 2008-2013 Chevrolet Silverado 1500, upstream right and upstream left. Fits 2007-2013 GMC Sierra 1500, upstream right and upstream left. Fits 2004-2012 Chevrolet Malibu, upstream right and upstream left. Fits 2006-2011 Chevrolet Impala, upstream right, upstream left, and upstream. Fits 2008-2010 Saturn Vue, upstream right, upstream left, upstream rear, and upstream front.

Before installation, confirm the sensor position, connector style, thread size, and harness routing against the original part. This NTK 21546 oxygen sensor is a specific-fit replacement, so matching the listed application and position is important for proper installation and operation.

Quality Assurance

NTK manufactures oxygen sensors with extensive testing during production to support OE-level reliability and consistent performance. As part of the NGK family of products and a major original equipment oxygen sensor supplier, NTK focuses on application coverage and manufacturing control for emission control service parts.