See Figures 1 and 2
The charcoal canister is part of the Evaporative Emission Control System. This system prevents the escape of raw gasoline vapors from the vehicle's fuel system to escape into the atmosphere.
The canister is designed to absorb fuel vapors under specific conditions. The canister is about the size of a coffee can and is located in the engine compartment. On some later model 2.0L (non-turbo) and 2.4L engines, the evaporative canister must be accessed through the passenger's side front wheel well.
The canister itself generally does not require replacement at a specific mileage however, the Evaporative Emission Control System does require a careful operations check at 50,000 miles or every 5 years, whichever comes first. Testing procedures are listed in Emission Controls of this repair guide.
If removal does become necessary, prior to removing the canister assembly from the vehicle, label the vacuum hose connections at the top of the canister. For proper functioning of the system, it is essential that the hoses be returned to their original locations.