Evaporative Emission Control Canister: Description and Operation

The fuel vapors from the fuel tank and carburetor bowl are stored in the carbon canister until the vehicle is operated, at which time, the vapors will purge from the canister into the engine for consumption. There are two canister sizes, that is, 925 ml and 1400 ml carbon. Canisters are sometimes used in pairs when the vehicle has a large fuel tank or dual tanks or dual bowls.