The charcoal canister or vapor canister is located under the vehicle, very close to the fuel tank. It is hidden under plastic covers, so it can be difficult to locate it.
What is a charcoal canister in a Toyota? Part of the car's emissions controls, this charcoal-filled canister's job is to absorb fuel vapor that would otherwise vent out to the atmosphere, causing pollution. Vapors trapped by the charcoal are released back into the engine through the purge valve and then burned.
