Evaporative Emissions System: Description and Operation

PURPOSE
The Evaporative Emission (EVAP) System is designed to reduce Hydrocarbon (HC) emissions by preventing raw fuel vapors from escaping into the atmosphere by the use of a Canister, Canister Purge Solenoid Valve, a purge port at the intake manifold and a vented fuel filler cap.

OPERATION
The system holds fuel vapor collected from the fuel tank in the Canister where it is stored until the Engine Control Module activates the Canister Purge Solenoid Valve and allows engine vacuum to draw fuel vapors into the combustion process.