See Figures 1, 2 and 3
A carbon filled canister stores fuel vapors until the engine is started and the vapors are drawn into the combustion chambers and burned. To check the operation of the carbon canister purge control valve, disconnect the rubber hose between the canister control valve and the T-fitting, at the T-fitting. Apply vacuum to the hose leading to the control valve. The vacuum condition should be maintained indefinitely. If the control valve leaks, remove the top cover of the valve and check for a dislocated or cracked diaphragm. If the diaphragm is damaged, a repair kit containing a new diaphragm, retainer and spring is available and should be installed.
The carbon canister has an air filter in the bottom of the canister. The filter element should be checked once a year or every 12,000 miles (19,323 km); more frequently if the car is operated in dusty areas. Replace the filter by pulling it out of the bottom of the canister and installing a new one.