See Figure 1
All vehicles are equipped with charcoal canisters. While the engine is inoperative, fuel vapors generated inside the fuel tank are absorbed and stored in the canister. When the engine is running, the vapors are drawn through the electronically controlled purge control valve and into the intake manifold. The vapors enter the air/fuel mixture and are burned in the combustion process.
The only service required for the charcoal canister is to replace the filter pad on the bottom of the canister. The filter requires replacement every 12 months or 12,000 miles. If the vehicle is driven under severe conditions, the filter should be replaced more often.