i just got my car back to day with the 3" y-pipe installed...haven't gotten the rest of it done yet, don't know what type of muffler to go with. anyway, while driving with the heater on i can smell it coming through the vents and when i get out i reek of exhaudt fumes...is this just because i only have the y-pipe on or could it be something else?

 

well i think i got it...4 header bolts, all at the back of the engine were loose. 2 of them i could spin w/my finger, after i tightened them all down car is actually running better and the AC and heater don't blow in exhaust gas.

 

You might want to check your cowl-to-hood seal while you're at it. You smelled it because it was unusually strong, but you're probably still getting unhealthy fumes from the engine compartment into the passenger compartment.

 

What if the seal is good (and I'm really asking seriously)?
I know on my beater (the 91' rs), if the windows are up... not a trace of smell (or my eyes burning as they are pretty sensitive to exhaust)... windows cracked or down... ripe smells of oil and unburned gas. With the window craked, it can be bad enough to have to roll it all the way down just to defume the cabin.
Rather annoying as it burns the hell out of my eyes as well.

I've never had this problem with any other car I've had. Even my old '84 sc w/no seal didn't do this.

 

that would be a nice faq. how to seal your compartment off from harmful chemicals/fumes or at least things to check to help prevent it.