Bosch Vapor Canister Purge Valves are a critical component in the proper operation of vehicle evaporative emissions control systems.The vapor canister purge valve helps prevent fuel vapor from escaping into the atmosphere by metering the flow of vapor from the active charcoal filter to the engine in accordance with the engine's operating state. You can install Bosch vapor canister purge valves with complete confidence knowing that they are of the highest quality and meet or exceed OE specifications in fit, form, and function.