Genuine OEM Audi Emissions Breather Line, part number 4G0201991J. This line is an integral part of the emissions system, designed to allow gases to escape safely and regulate pressure within the system. It is positioned at the rear right of the vehicle. Weighing approximately 0.06 kg and measuring 0.56 meters in length. Using a genuine OEM breather line ensures correct material resistance to exhaust gases, precise routing, and proper sealing, which are critical for maintaining emissions compliance and system reliability.