The Evaporative Emission System is used to reduce hydrocarbon emissions from the fuel system to the atmosphere, which is achieved through the presence of activated carbon in the EVAP filter.
While the engine is not running or while the tank is being filled with fuel, fuel vapors from the sealed fuel tank pass into the EVAR filter where they are retained.
When the engine is running, the EVAP filter is purged with air that is sucked through the purge tube into the top of the intake manifold. The EVAP charcoal filter purge solenoid valve is controlled by the ECM. When the engine is running, the vapor flow rate is controlled by the EVAP carbon filter purge solenoid valve in proportion to the increase in air flow.
The EVAP charcoal filter purge solenoid valve also serves to cut off vapor purge when decelerating.