gas fumes thru AC on a '01 toyota corolla

If you detect the odor of gasoline then there is a leak. Probably in the emissions systems and probably vapor not liquid gasoline. When you say "everyone" do you mean mechanics at either the corner shop or dealer? All vacuum hoses need to be thoroughly inspected, look for one fallen off..cracked, deteriorated, whatever and also get your OBD codes scanned at any large parts house. Often they can pinpoint the culprit....or at least point you in the right direction. Check you gas cap. If you get any codes....P followed by 4 numbers..P0000..bring them back here and one of us will be happy to help you make a decision on what to do. You have a 1ZZ FE 1.8Liter. Meantime, is is less likely, but if there is a leak of liquid gasoline there is a risk of fire, please get those codes post haste because of that.

Thanks Mr. David. But I think this problem is related with Air Conditioning System because of odor only comes when AC switch ON and duration may be 1-2 minutes only. So that I think it will happen for chemical reaction between inside air and poly-ethylene which has been used for car interior. You can replace the ac filter and used charcoal filter must.It is correct? ---Mofazzel Hossain/Toyota Service_Bangladesh

Well this is how i see it. 4 yr;s ago i got a check engine light in my 2001 Toyota Corolla so i had it scanned. The problem was suppose to be a (Clogged Charcoal Canister) and it seemed to be the fix and it did clear the code. It's been 4 yr's and have not seen the light again. So now i have the feeling they never fixed the problem that ruined the Charcoal Canister. The Problem seems to be it's getting much fuel on a cold start. (Worst in winter).Still get the smell of Fuel on a cold start but it seems to go away within minutes. It has nothing to do with your Air Conditioner, the smell is coming from the engine compartment and getting sucked in threw the Air Conditioner.