EVAP System Function

The evaporative emission (EVAP) control system limits fuel vapors from escaping into the atmosphere. The fuel tank vapors are allowed to move from a sealed fuel tank, due to pressure in the tank, through a vapor pipe into the EVAP canister. Carbon in the canister absorbs and stores the fuel vapors. Excess pressure is vented through the vent line and vent valve to atmosphere. The EVAP canister stores the fuel vapors until the engine is able to use them.