Q: How Does the Evaporative Emission Control System (EVAP) Work and How Can You Replace canister on Ford Excursion?
A: The Evaporative Emission Control System (EVAP) traps and stores fuel vapors from the fuel tank, throttle body, and intake manifold when the engine is idle. The system includes a charcoal canister, fuel vapor management valve (VMV), fuel tank pressure sensor, and other components. The vapors are in the canister when the engine is off and purged when it is running and the fuel tank pressure sensor informs the PCM, which regulates the EVAP system. To replace the charcoal canister, relieve the fuel tank pressure and disconnect the purge control solenoid. Remove the outlet hose and mounting bolt, and remove the canister. To replace the VMV, disconnect the electrical connector, label and disconnect the vacuum hoses, and remove the mounting bolts. Installation is the reverse of removal.