2003 Dodge Caravan Engine Light Came On

2003 Dodge Caravan Two Wheel Drive Automatic 91000 miles

The engine light is on, however I cannot tell that there is anything wrong. The garage states the code reads there's leaking air. (Something like ABC Leak). My father-in-law guesses its the charcoal canister? Do you have any idea where to start looking or what could be the problem?