My "Service Engine Soon" light came on and I smell gas... especially through the vents when the AC is on

Question

1999 Grand Am GT, 3400, SFI. I've checked under the car.. there are no signs of dripping gasoline. A friend of mine checked the gas cap through emissions testing and it failed. So I bought another gas cap and he reset the computer on my car and the light came back on 2 days later. The test results were "evaporator leak" (small leak)

I took it back 2 days later because the light came back on and this time the emissions testing came up with two problems, but he can't tell what they are. He reset my computer again and the light came back on again.

Answer 1

if you smell gas today and you have had the car awhile and didn't smell gas before, then there is a good chance you have a fuel leak. it would be stronger coming through the vents with the fan blowing if you have the recirculate function turned off. fuel leaking will not always be visible from underneath the car because gasoline evaporates very quickly and if the leak is small you won't see it from under the car, you will smell it even if it is a very slow leak but you will not see it under the car like you can see an oil leak. also, my "service eng soon" light on my fiero lights up when the oxygen sensor comes unplugged. fiero is pontiac also.

Answer 2

if you overfill the fuel tank the fuel will flow from the tank through the evap lines into the canister under the hood.when you fill the car stop fueling when the nozel stops automatically.i am ase certified tech and have seen this many times.

Answer 3

ck lines leaving gas tank going to evap solenoid on engine.also ck canister for hoses leaking fuel vapors. you may have to have a leak test performed with special evap tester.,a dealer tool.

Answer 4

oxygen sensor