Toyota 77740-48080 Canister Assy, Charcoal

The Evaporative Emissions Control (EVAP) system serves to absorb fuel vapors and release them into the intake manifold during engine operation. It comprises the fuel tank filler neck cap, EVAP canister, vapor pressure sensor, canister closed valve, pressure switching valve, and purge valve. The EVAP canister's contents are purged when the pressure inside the sealed fuel tank increases due to fuel evaporation, and the canister stores vapors until the PCM initiates purging through the purge valve, allowing vapors into the intake manifold. The vapor pressure sensor on the fuel tank monitors pressure, signaling the PCM to open the pressure switching valve for purging. A purge valve regulates vapor flow, while the canister closed valve vents atmospheric air during purging and closes for testing. The EVAP system undergoes a diagnostic monitor to check for leaks, involving purging, pressure change monitoring, and venting checks. Replacements involve disconnecting the negative battery terminal, removing engine covers if applicable, disconnecting connectors, vacuum hoses, mounting screws or bolts, and then installing replacements following the reverse process. The EVAP canister's location varies, with different components serviced depending on the model year.