Genuine OEM Volkswagen Reducing Agent Injector Metering Line, part number 3Q0131984AD. This critical component is responsible for precisely delivering the reducing agent, such as AdBlue or Diesel Exhaust Fluid (DEF), from its reservoir to the injector within the exhaust system. It plays a vital role in the Selective Catalytic Reduction (SCR) process, significantly reducing harmful nitrogen oxide emissions. The line is routed to ensure optimal flow and pressure for the emissions system. Weighing approximately 0.34 kg, it is engineered for durability and resistance to the reducing agent. Using a genuine OEM metering line ensures correct routing geometry, material compatibility, and leak-free operation, which is essential for maintaining emissions compliance and system integrity.