What is the function of a car's charcoal canister?

[StLorenzo]

The function of a car's charcoal canister is to prevent fuel vapors from escaping into the atmosphere after the engine stops running. Gasoline is a highly volatile liquid, and at normal temperatures, the fuel tank often becomes filled with vapors. These vapors can escape into the atmosphere, leading to air pollution. Therefore, vehicles are equipped with an evaporative emission control system, which directs these vapors into the combustion process and prevents them from evaporating into the atmosphere. The key component of this system is the charcoal canister, which contains activated carbon. Situations that require checking the charcoal canister include: 1. When the engine is running at non-idle speeds, if you occasionally hear a clicking sound, and this sound is emitted by the canister's electronic valve, it is normal. If the sound is not from the electronic valve, a thorough inspection is needed. 2. If you experience vehicle hesitation when accelerating by pressing the throttle, accompanied by a strong gasoline smell inside the car, special attention should be paid to whether the pipes in the charcoal canister system are damaged. This indicates that the vapors from the fuel tank are not being absorbed by the charcoal canister and are instead entering the car's interior.