Dorman 904-421 Nitrogen Oxide (NOx) Sensor - Downstream

Reliable Nitrogen Oxide Sensor for Chevrolet and GMC Vehicles

The Dorman 904-421 Nitrogen Oxide (NOx) Sensor is designed specifically for select Chevrolet and GMC models, including Express, Savana, Sierra, and Silverado series. This sensor helps maintain proper emission control by accurately monitoring NOx levels, ensuring your vehicle meets environmental standards.

• Color: Silver with a plain finish for durability
• Wiring harness length: 920 mm for precise fitment
• Wire gauge measurement: 22 for optimal electrical performance
• Connector color: Black and silver with a rounded rectangle shape
• Terminal type: Pin with 6 terminals (male) and female connector
• Specific fit designed for Chevrolet and GMC heavy-duty models
• Package includes one sensor with module

Detailed Description of the Dorman 904-421 NOx Sensor

This Dorman NOx sensor features a silver, plain finish housing that provides reliable operation under harsh engine conditions. The 920 mm wiring harness length and 22-gauge wire ensure proper connectivity and signal transmission. The sensor’s connector is a rounded rectangle shape in black and silver, equipped with six male pin terminals and a female connector, designed for a secure and precise fit. This sensor is engineered specifically for heavy-duty Chevrolet and GMC vehicles, including Express 2500/3500, Savana 2500/3500, Sierra 2500 HD/3500 HD, and Silverado 2500 HD/3500 HD models, ensuring compatibility and performance.

Common Applications and Issues Addressed

• Helps maintain accurate NOx emissions readings for compliance with emission regulations
• Prevents engine warning lights related to emission sensor faults
• Supports proper functioning of the vehicle’s emission control system
• Reduces risk of failed emissions tests due to faulty NOx sensor readings
• Improves engine performance by providing accurate exhaust gas data

Installation Notes and Tips

When installing the Dorman 904-421 NOx sensor, ensure the wiring harness is routed without sharp bends or contact with hot engine components. Verify the connector securely mates with the vehicle’s harness to avoid signal interruptions. This sensor is a direct replacement designed for specific Chevrolet and GMC models, so no modifications are typically required. Consult the vehicle’s service manual for torque specifications and sensor location details.

Quality Assurance and Warranty

Dorman manufactures this NOx sensor to meet or exceed OEM specifications for fit, form, and function. While specific warranty details are not provided here, Dorman products generally come with a limited warranty covering defects in materials and workmanship. For exact warranty terms, refer to Dorman’s official documentation or contact the distributor.