Dorman 911-983 Secondary Air Injection Check Valve - Left

Secondary Air Injection Check Valve for OE Fit

The Dorman 911-983 secondary air injection check valve is built to match the fit and function of the original valve on specified vehicles. It is engineered for durable, reliable performance in the secondary air injection system, with a diaphragm valve design and a temperature range from -40C to 125C.

Compatible with select Audi A4, A4 Quattro, A6, A6 Quattro, S6, and A8 Quattro models, as well as Volkswagen Passat, Touareg, and Phaeton applications, this Dorman 911-983 valve supports proper air management in emission control systems. It is a direct-fit replacement for vehicles that use a 0.675 in inlet and outlet size and a 50 psi maximum pressure rating.

Key Features

• OE-style secondary air injection check valve for emission control repair
• Diaphragm valve design for controlled airflow in the air injection system
• Aluminum, brass, and plastic construction with grey finish
• 0.675 in inlet and outlet sizes for specified applications
• Rated for up to 50 psi and -40C to 125C operating temperatures
• Direct replacement for Dorman 911-983 applications

Detailed Description

Dorman 911-983 is a secondary air injection check valve designed for specified Audi and Volkswagen vehicles where the original valve has failed or no longer seals correctly. By matching the original fit and function, it helps restore proper operation of the secondary air injection system and supports emission control performance. This part cross-references Standard Ignition DV170 for the same application.

Use this valve on fitments including 1997-2001 Audi A4, 1997-2001 Audi A4 Quattro, 1997-2001 Audi A6, 1997-2001 Audi A6 Quattro, 2001-2004 Audi S6, 2000-2006 Audi A8 Quattro, 1998-2005 Volkswagen Passat, 2004-2006 Volkswagen Phaeton, and 2004-2007 Volkswagen Touareg, left. The Dorman 911-983 is also listed with interchange reference 078131101AC.

Common Problems This Part Addresses

• Secondary air injection fault codes related to valve sealing or flow issues
• Emissions system performance problems caused by a worn check valve
• Air backflow in the secondary air injection circuit
• Rough cold-start emissions behavior tied to air injection malfunction
• Replacement needs after corrosion, cracking, or diaphragm wear

Installation Notes and Tips

Verify the inlet and outlet dimensions, pressure rating, and left-side fitment before installation. Confirm the vehicle application against the listed Audi and Volkswagen model years, and inspect connected hoses and mounting points for wear or contamination before installing the new valve. Proper installation is important for correct sealing and system operation.

Quality Assurance

This Dorman emission control component is engineered to match original valve fit and function and to deliver dependable performance in specified applications. It is built for durability across a wide operating temperature range and is intended as a direct replacement for the original secondary air injection check valve.