Evaporative Emission (EVAP) Systems
WARNING: This page is about a different car, the 2021 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The EVAP system prevents fuel vapor build up in the sealed fuel tank. Fuel vapors trapped in the sealed tank are vented through the vapor valve assembly on top of the tank. The vapors leave the valve assembly through a single vapor line and continue to the EVAP canister for storage until the vapors are purged to the engine for burning.
All applications required to meet OBD regulations use the enhanced EVAP system.