The charcoal canister is part of the Evaporative Emission Control System. This system prevents the escape of raw gasoline vapors from the fuel tank and carburetor.
This system is designed to contain gasoline vapor, which normally escapes from the fuel tank and intake manifold, from discharging into the atmosphere. Vapor absorption is accomplished through the use of a charcoal canister, which stores the vapors until they can be removed and burned in the combustion process.
The charcoal canister is designed to absorb fuel vapors under certain conditions. For a more detailed description and removal and installation, see Emission Controls of this guide.
The canister is a coffee can-sized object located in the engine compartment.
The canister does not require periodic replacement. The entire system requires a careful operational check with a vacuum gauge at 60,000 miles (96,000 km). See Emission Controls for testing and removal procedures.