Evaporative Emission Control System Operation

Gasoline vapors produced in the fuel tank are collected in the canister. During normal engine operation, the purge control valve opens and closes, depending on throttle angle and intake manifold vacuum. The PCM turns on the purge control valve to use engine vacuum to draw fresh air through the filter on the side of the canister, through the two way valve, through the canister where it picks up stored fuel vapors, and into the intake manifold where the vapors are burned during normal engine operation.