Fuel Evaporation System: Description

All Light and some Heavy Duty emissions models are equipped with an Evaporative Emission Control System (EECS), designed to prevent raw fuel vapors from escaping to the atmosphere. System consists of special fuel tank with expansion section; venting system which allows only vaporous fuel to be drawn into the system; pressure-vacuum relief valve in gas cap to control tank pressure; and vapor-storing charcoal canister.