87 5.0 - Exhaust in cab..help!

[sunshadowGT]

I have an 87 mustang LX 5.0 conversion that is gettin exhaust in the cab. I checked the pipes for leaks, but I am not getting any leaks at the headers, the H-pipe, the cats, the mufflers or at the tailpipes.

It has a new Flowmaster cat-back on it.

I replaced the weather strips on the hatch and the two doors (since the original ones were torn to shreds) and I am still getting exhaust in the cab.

Has anyone else had this problem?

Are there any other intrusion points on the undercarriage where exhaust could be getting in?

It's driving me nuts and I almost passed out on the road the other day from the fumes.

Any help would be appreciated!

 

[96SVTpilot]

Unless you have some rotted pipes the most likely place for leaks is going to be at your 4 socket/ball connections at either end of the h-pipe. Usually you can tell a leak by the telltale black soot around the leak. If you just put a catback on you may not be able to tell that easy if there is a leak unless it is cold out and you can see the exhaust. If you nail the throttle and is sounds like an old chevy truck then there probably is a leak somewhere. If you can smell it while your driving then you definately have a leak. Normally you only smell it when you are idling and the exhaust can linger and filter up through the car. I would check for any cracks in your floorpan, missing bolts, and your seals around the e-brake cable and shifter housing.