The Pierburg Secondary Air Injection Pump - 722166390 is a component used in the secondary air injection system of a vehicle. This pump helps to reduce emissions by injecting air into the exhaust system, which helps to burn off any remaining fuel before it is released into the atmosphere. It is a high-quality, durable pump designed to meet strict emissions standards and improve overall engine performance. This product is compatible with a variety of vehicle makes and models and is an essential part of the secondary air injection system.