Evaporative Emission (EVAP) Canister

The EVAP canister stores unburned fuel vapors and prevents them from escaping into the atmosphere. The EVAP canister contains a carbon filter bed which holds fuel vapors until they are purged into the intake manifold through the EVAP purge solenoid. Fresh air normally flows though the [1][2]EVAP vent solenoid to the EVAP canister, then into the fuel tank to keep the fuel tank at atmospheric pressure.