Genuine OEM Audi Reducing Agent Injector Metering Line, part number 4H4131984D. This component is vital for the vehicle's emissions control system, accurately delivering the reducing agent (such as AdBlue/DEF) from its reservoir to the injector for exhaust gas treatment. It is typically situated in the front area of the vehicle's underbody or engine bay. Weighing 1 kg and measuring 0.4m x 0.3m x 0.06m, this line is engineered for durability and chemical resistance. Opting for a genuine OEM metering line ensures correct material composition, precise fitment, and reliable performance, which are essential for maintaining optimal emissions reduction and system longevity.