Genuine OEM Volkswagen Reducing Agent Injector Metering Line, part number 3Q0131984AG. This line is responsible for precisely metering and delivering the reducing agent (e.g., AdBlue/DEF) to the injector, which then sprays it into the exhaust system for NOx reduction. It is positioned within the emissions control system, connecting the reducing agent reservoir to the injector. Weighing 0.293 kg and measuring 0.39m in length, this line is engineered for durability and chemical resistance. Choosing a genuine OEM line ensures correct fluid delivery, preventing leaks and maintaining the precise dosing required for optimal emissions performance and system longevity.