i'am a newbie with this car, but i was cleanin the motor, and ther is a tank on the left side of the radiatior at the bottom, what is that??? it has 2 lids on it, with 2 hoses running to the bottom side of it?
no gas in it... but when you store gas (I.IE gas tank) and move it around pressure builds up (like a coke bottle but not exactly). it can eventually become dangerous, especially with a pump that could heat up some, so the fumes are vented through that thing. you can ditch it, but your car will reak or gasoline and its not the safest idea either.
if you are talking about the tank on the passenger side, yep, Paul is right on. it contains vapors and uses a solenoid to inject the vapors back into the intake (purge).
I just did h/c/i swap on my car. When we did it we took the motor out and put a new oil pump in and ****. So while it was out i took the carbon canister off. Im sure it has nothing to do with it, but it seems like my car is getting better gas mileage than it was before. So im not sure if it helps mileage or not, I think it just for emissions. Just my opinion.
in the old days fuel vapors were vented into the atmosphere. That is no longer cool, so the relatively complex EVAP system keeps those fumes from being vented into the air (closes the system).
There should be no tangible fuel economy benefit that I can see, but who knows.