Genuine VW/Audi Secondary Air Injection Pump Check Valve - 022131101G - This check valve is a genuine OEM part designed to replace the original valve in your Volkswagen or Audi vehicle. It is made from high-quality materials for durability and reliability. It is designed to prevent air from entering the engine from the secondary air injection system, thus preventing engine damage. It is an essential part of your vehicle's emissions system, and should be replaced regularly for optimal performance.