On my truck there is this canister that several people say its a carbon gasoline fileter. My hanes book shows nothing about it. Its on the front right side of the engine bay and the fuel lines are connected. So the main reason of me telling you all of this is three questions. 1. What the hell is it!? 2. Why do i need it? 3. If i take it out,will i get better MPGs, And if so how hard is it? I cant find anything about it and everybody just says "DONT **** WITH IT!!!" . I just want to know what the hell it is because nobody that ive talked to knows for sure.

 

what kind of truck is it? if its an older truck that uses the canister system, leave it. that is your charcoal canister that is part of your evap system and will throw a code if removed.

 

Its a 91 4.3 half ton. What does it do?