^ i don't know exactly. i'm guessing it traps fuel vapors for the carb to use upon startup.

most taxis remove it, makes no difference to engine. when i removed the broken one, had to crank the engine 3 times before it fires up in the morn.

since the car's not mine, i went out and replaced the canister valve na rin... mahirap na masisi lalo na't sa in laws ko yun hahaha