NTK 21004 Oxygen Sensor - Upstream

Overview of NTK Direct Fit Oxygen Sensor 21004

The NTK Direct Fit Oxygen Sensor 21004 is engineered for precise emission control in select Buick, Chevrolet, GMC, Oldsmobile, and Pontiac vehicles. Designed as a heated oxygen sensor with a specific fit, it ensures accurate air-fuel mixture readings to maintain optimal engine performance.

• Heated oxygen sensor for faster response times
• Specific fit for select GM models including Chevrolet Tahoe and GMC Yukon
• Threaded mounting type with 18mm thread diameter
• 12.25-inch wiring harness length for direct installation
• Three-wire configuration for reliable signal transmission

Features of the Direct Fit Oxygen Sensor Line

The NTK Direct Fit Oxygen Sensor product line focuses on providing exact replacement sensors tailored to specific vehicle applications. This approach eliminates the need for modifications during installation and ensures compatibility with factory wiring and connectors. The 21004 sensor exemplifies this by offering a direct fit solution for various GM trucks and SUVs, maintaining emission standards and engine efficiency.

Detailed Product Description

The NTK 21004 oxygen sensor is a heated sensor type, which means it includes an internal heating element to bring the sensor up to operating temperature quickly. This feature improves sensor responsiveness and reduces emissions during cold starts. The sensor’s 18mm threaded mounting allows for secure installation in the exhaust system, while the 12.25-inch wiring harness length provides sufficient reach for direct connection without splicing. With three wires, this sensor supports both the signal and heater circuits, ensuring accurate data transmission to the engine control unit (ECU).

Compatible Vehicles and Common Applications

• Buick LeSabre and Park Avenue
• Chevrolet C1500, C2500, C3500, Tahoe, and Lumina APV
• GMC K1500, K2500, K3500, Yukon, and Safari
• Oldsmobile 88 and 98 models
• Pontiac Bonneville and Trans Sport

Issues Addressed by NTK Oxygen Sensor 21004

• Incorrect air-fuel mixture readings causing poor fuel economy
• Check engine light triggered by faulty oxygen sensor signals
• Increased emissions due to delayed sensor response
• Engine performance problems such as rough idling or hesitation
• Failed emissions tests related to sensor malfunction

Installation Notes and Tips

Installation of the NTK 21004 oxygen sensor requires removal of the old sensor from the exhaust manifold or pipe. Use an oxygen sensor socket to avoid damage during removal. Ensure the wiring harness is connected securely to the factory connector without cutting or splicing. The 12.25-inch harness length is designed for direct fitment in compatible GM vehicles. After installation, clear any diagnostic trouble codes and verify sensor operation with a scan tool.

Quality Assurance and Warranty

NTK oxygen sensors are manufactured to meet OEM specifications for durability and performance. The Direct Fit Oxygen Sensor 21004 undergoes rigorous testing to ensure reliable operation under various driving conditions. While specific warranty details may vary, NTK typically offers coverage against defects in materials and workmanship to support long-term use.