Help!! Anyone Know What This Could Be?
 

I have a 1997 Mustang GT, Last night I was driving it home and it sounded as if it had a little exsuast leak, well it seemed ok this morning and I drove it to work, well leaving work it sounded fine until I was just about home, then it started to sound like I had no exhaust at all, I crawled under the car the exhaust it all on there it seems to been fine. The car is the same it sounds like there is no exhaust on it. HELP!!! Does anyone have any ideas of what it may be?? I do not even know where to being. The car has the 4.6, I put the off road hipe pipe on it and flowmaster mufflers. Please let me know if anyone has had this problem or has any suggestions.

I have the same exact thing with my car. Does it sound like its coming from the passenger side, maybe up by the header? If so, I am thinking it may be the gasket that came with the pipe. To see if you have an exhaust leak, have a friend help you to plug up both exhaust pipes. If you hear a squeal or whistle, then there is a definite leak. You may not be able to hear the leak at the header like I think is my problem. My car usually only does it when the car is under a load, but again, I couldnt hear any leaks. When I get my car's chip re-tuned an the dyno, I'm gonna have the shop see if they can find anything.

This is a definite leak or something else. The car is very very loud and it is not running right, But there is no apparent leaks or places that I could tell that would cause the car to sound as if it has not exhaust at all,

Try this before you do anything else. If not, then it may be something worse.

if your running your stock exh manifold, header's, ck the gasket on the pass side, when i put my x-pipe on my old one was fine, so i didnt put my new gasket on, saving it. :)just get a new ford gasket, not that expensive.

I did put the new gasket on. If I cant get mine to stop doint what its doing, im gonna try taking the gasket off.

ok was it a ford gasket or aftermarket?

It was the aftermarket one that came with the Mac Prochamber.

I am not really on the up and up on the modular cars, but, I had a similar problem with my 90 gt and it was the hose that runs fromthe smog pump to the X pipe. Do the modular cars have these hoses? If so check it, mine melted. Just a thought.
Caymon