Genuine OEM Audi Secondary Air Injection Hose, part number 07K131128D. This flexible hose is a critical component of the secondary air injection system, responsible for delivering fresh air to the exhaust stream. This process helps to reduce harmful emissions during cold starts by promoting faster catalyst warm-up. Made from durable, heat-resistant rubber, it is designed to withstand engine bay temperatures and vibrations. Choosing genuine OEM ensures the correct material composition, precise routing geometry, and secure connections, which are essential for maintaining emission compliance and engine efficiency.