charcoal canister needed or not

[mellow65]

the basics here, got a 90 legacy im putting a 99 forester motor in it the forester EVAP system basically have the vapors from the tank running through a solenoid and then directly to the intake. no charcoal canister to be seen.

 

the 90 legacy has the vapors from the tank running to a charcoal canister then to a solenoid then to the intake.

 

so to simplify things would it hurt any thing by removing the charcoal canister. the vapors would still be pulled into the intake when the computer wants it to be but just not ran through a charcoal canister.

 

would it have any ill effects by taking it out

 

i still would have it hooked up like the forester had it just no charcoal canister

[OB99W]

A '99 Forester without a vapor canister?

 

The EVAP system doesn't exactly pull gas vapors "through" the canister; the charcoal "stores" the vapors, and the system extracts them when it can do so without compromising engine operation. I suspect that you'd find removing the canister will make the ECU unhappy when it tries to run the EVAP, and will tell you so via the CEL.

[idosubaru]

i have a 1996 Legacy GT without a canister and a 1997 Impreza OBS automatic without one as well (although two other identical impreza's did have one). i'm about to install one of them in my Legacy LSi that did have a canister. this one actually doesn't have EGR either so i will definitely have something to deal with.

[WoodsWagon]

The ones "without" a cannister actually have it in the back. It's a rectangular box behind one of the wheelwells underneath. The vacuum line doesn't pull fumes from the tank into the intake. It pulls fresh air through the carbon canister, which evaporates the gas absorbed in the carbon and sucks that into the intake. If you hook the vacuum line directly to the evap hose coming from the tank, you will pull a vacuum on the tank. This will make the fuel pump work harder, and if the gascap doesn't have a vacuum relief, crush the gas tank.

 

If you look at the carbon cannister on the car that has it next to the airbox, you will see 3 hoses hooked up to it. One from the tank, the big one, one from the vacuum solenoid, the small one, and another big one coming out from the bottom of the cannister and running into the framerail. This is the fresh air vent.

[idosubaru]

The ones "without" a cannister actually have it in the back. It's a rectangular box behind one of the wheelwells underneath.

oh sweet - passengers or drivers side? is it easy to see under there?

[mellow65]

The ones "without" a cannister actually have it in the back. It's a rectangular box behind one of the wheelwells underneath. The vacuum line doesn't pull fumes from the tank into the intake. It pulls fresh air through the carbon canister, which evaporates the gas absorbed in the carbon and sucks that into the intake. If you hook the vacuum line directly to the evap hose coming from the tank, you will pull a vacuum on the tank. This will make the fuel pump work harder, and if the gascap doesn't have a vacuum relief, crush the gas tank.

 

If you look at the carbon cannister on the car that has it next to the airbox, you will see 3 hoses hooked up to it. One from the tank, the big one, one from the vacuum solenoid, the small one, and another big one coming out from the bottom of the cannister and running into the framerail. This is the fresh air vent.

 

i always wondered what the hell that thing was back there.

 

well i was able to plum all the vacuum lines like it was off of the 2.2 so it shouldn't be an issue now. but at least i got one question answered i had always wondered, what the hell is the black box in the passenger rear bumper.

[Andyjo]

carbon canister on my 97 OBS is located rear pass. side.

[idosubaru]

in the passenger rear bumper.

it's not in the bumper is it?

[WoodsWagon]

It's behind the side of the bumper cover, on the "frame rail", right where a trailer hitch attaches. Look directly behind the wheel well under the car.