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Charcoal canister replacement - opinions on if this is necessary?

I have a 2007 Subaru Forester with almost 61,000 miles. The check engine light has come on several times over the past several months. The dealership says the code (P0442) indicates an evap leak. They first suggested a new gas cap. This didn’t fix the problem.

Yesterday I took it to the dealership and they did a smoke test to see where it might be leaking. The first issue that came up was the charcoal canister. They said there was liquid fuel in it (from me topping off the gas tank) and I need a new canister ($481.85) and then they will re-test to see if it leaking anywhere else.

My question is if this is really needed or not. If I stop topping off the gas tank, will the canister dry out and be OK? I am just really suspicious of dealerships…it seems like most of them try to gouge you for as much money as they can. The service guy said I could wait a little while to replace the canister but if I wait too long other things could be damaged.

Any thought or suggestions about any of this?

You seem to have defined “necessary” well enough for me. I don’t know if anything else will be damaged or if there is a fire hazard involved. If neither bad situation applies, you can form your own answer because it seems that you don’t live in a state that does “smog system inspections”.

Finally! A Subaru without head gasket problems. You’re driving a gem; so go ahead and get your wallet flushed.

“If I stop topping off the gas tank, will the canister dry out and be OK?”

Probably, yes. I can’t say for sure since there might be some valve malfunction somewhere causing the canister to stay wet. If the valve is part of the canister itself then replacement of the whole unit might be the only cure.

Since the malfunction that lights the CEL is not affecting drivability, I would certainly drive it for at least two more half-tanks to see if the condition rights itself. I don’t see any further damage arising from this attempt.

“If I stop topping off the gas tank, will the canister dry out and be OK?”

It did for me on my 97 Nissan truck.