A: To begin with, evaporative emissions control system is designed to draw fuel vapors from the gas tank and fuel system, store them in a charcoal canister, and route them to the intake manifold when the engine is running. In case of a problem with this system, it could be detected immediately due to strong fuel odor within the engine. If there are smells of gasoline, you should check the charcoal canister under the master cylinder located at the engine compartment. The driver's side firewall in the engine compartment houses the charcoal canister. Check for damage and wear on all hoses as well as on canister; it's important.