Evaporative Emissions: Canister-Vapor: Operation
WARNING: This page is about a different car, the 2005 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
The EVAP canister is filled with granules of an activated carbon mixture. Fuel vapors entering the EVAP canister is absorbed by the charcoal granules.
Fuel tank pressure vents into the EVAP canister. Fuel vapors are temporarily held in the canister until they can be drawn into the intake manifold. The duty cycle EVAP canister purge solenoid allows the EVAP canister to be purged at predetermined times and at certain engine operating conditions.