NTK 21576 Oxygen Sensor - Downstream Left or Downstream Right

Overview of NTK Direct Fit Oxygen Sensor 21576

The NTK Direct Fit Oxygen Sensor 21576 is designed for precise emission control in select GM and Isuzu vehicles. This heated oxygen sensor ensures accurate air-fuel mixture readings, helping maintain optimal engine performance and emissions compliance.

• Heated oxygen sensor for faster response times
• Specific fit for Buick, Chevrolet, GMC, Isuzu, and Saab models
• Threaded mounting type with 18mm thread diameter
• Four-wire design for reliable signal transmission
• 13.75-inch wiring harness length for proper installation

Detailed Product Description

This NTK oxygen sensor, part number 21576, belongs to the Direct Fit Oxygen Sensor line, which focuses on providing exact replacement sensors tailored to specific vehicle applications. The heated sensor element allows quicker activation, improving fuel efficiency and reducing emissions shortly after engine start. With a threaded mounting type and an 18mm thread diameter, this sensor installs securely in the exhaust system. The four-wire configuration supports both the sensor signal and heater circuit, ensuring consistent operation. The 13.75-inch wiring harness length is designed to match factory specifications, simplifying installation without the need for modifications.

Compatible Vehicles and Applications

This oxygen sensor is compatible with a range of vehicles including Buick 9-7x, Chevrolet Trailblazer and Trailblazer EXT, GMC Envoy and Envoy XL, Isuzu Ascender, Saab 9-7x, and several GM Express and Savana 1500 models. It is intended for use in emission control systems to monitor oxygen levels in the exhaust gases and provide feedback to the engine control unit.

• Helps resolve rough idling caused by incorrect air-fuel mixture
• Addresses increased emissions and failed emissions tests
• Corrects poor fuel economy related to faulty oxygen sensors
• Eliminates check engine light triggers related to oxygen sensor faults
• Improves overall engine performance and drivability

Installation Notes and Tips

When installing the NTK 21576 oxygen sensor, ensure the engine and exhaust system are cool to avoid burns. Use an oxygen sensor socket or appropriate tool to remove the old sensor carefully. Verify the wiring harness length and connector match the vehicle’s factory setup to prevent electrical issues. Apply anti-seize compound to the threads if recommended by the vehicle manufacturer, but avoid contaminating the sensor tip. Torque the sensor to the specified value to ensure a proper seal and function.

Quality Assurance and Warranty

NTK’s Direct Fit Oxygen Sensor line is engineered to meet or exceed OEM specifications for fit, form, and function. Each sensor undergoes rigorous testing to ensure durability and reliable performance under various operating conditions. While specific warranty details may vary, NTK typically offers coverage against defects in materials and workmanship, providing confidence in the sensor’s long-term reliability.