what can cause a REALLY bad smell of gas when you start the car that will go away after probably less than 3 or 4 seconds? i have checked all the fuel lines for leakage as well as the gas tank. i have changed the Evap or charcol canister filter(dont see how that will make a difference but the GM mechanic said it would and it was only 2.33 with tax).

 

your cold start injector may be leaking

 

Oh. hmm thats gonna suck to fix.

 

disconnect the harness going to it & see if it stops fuming