Metal Head

OK, here's the story.
I have a 99 GT auto, it has all the bolt-ons.

I am trying to track down what seems to be exhaust fumes getting into the car.

It's weird because I don't actually smell anything, but after about five minutes of driving my throat starts to burn, my eyes water, I get sick in the stomach, and I get real dizzy. Whatever it is has no odor. I keep the windows rolled down to get as much fresh air as possible, but after about 20 minutes I'm so sick I have to get out the car and get some fresh air. This problem started about two months ago.

Things I've already tried:

I suspected the problem was a clogged catalytic converter, so I pulled out my old MAC h-pipe and put in a brand new BBK h-pipe with no cats. The old H-pipe had a pretty burnt up looking cat on the driver's side. However, this did not fix the problem.

I suspected the corroding/flaking MAC headers were causing the fumes, so I had a brand new set of BBK headers put in. But the problem is still there.

I suspected a fuel/ignition issue. I had a Ford dealer diagnose the ignition, and one of the coil packs was starting to go bad. Replaced the coil pack, replaced the sparkplug on that coil pack. The car runs better, but this did not fix the fumes problem.

I had a Diablo Predator tune installed to try to burn off any excess fuel. The gas mileage went WAY down, and I picked up some horsepower. But the fumes have not went away.

I'm running out of ideas and $$$ and I still can't drive the car without getting sick in a few minutes.

Here are some things I plan on doing this weekend, but after that, I'm totally stumped (and broke).

-Replace EGR valve
-Replace PCV valve
-Replace ALL O2 sensors

Can anybody help??
Any help is greatly appreciated. I really want to keep this car.

Thanks.

BraMas

My guess is you have an exhaust leak somewhere
Check all the spots where 2 Pieces of exhaust bolt together. You can either take it to a Muffler shop and have them find it or put the car on jack stands crawl under car and have a friend rev it while you feel for exhaust escaping from joints. Don't touch the pipes just close enough to feel exhaust.

baino

+1, sounds like you have exhaust leaking out of your mid pipe either at headers or catback.

oxfordgt

Check your tailpipes. Make sure a crazy ex didn't stick a hose in there and run it into the car

Park the car on tall grass then let it cool all the way. Start it and look under it for grass moving. Where the grass moves is where to look for the leak.

Metal Head

The headers are brand new, and so is the H-pipe. No corrosion or anything else preventing a good seal. The only thing left would be my flowmasters. You think the mufflers are stopped up somehow or otherwise leaking?

Thanks.

BraMas

Have you checked your header bolts?
Just becasue something is new does not mean that it did not seal correctly. Make sure you check all parts even if they are new

vanquish

yeah make sure all your connections are tight

mlax

Man I had the same thing. I replaced the motor this winter and when I started driving it I could smell exhaust. I took it back to the shop and one of the cats was clogged. We knockded out the insides and gutted it and I had the same problem. We put it back on the dyno and tried to fix it with the air/fuel mix. That did not work. We then replaced the cats with new ones and completly welded all exhaust connections. This fixed the problem. I would try welding all the exhaust joints instead of using clamps and see if that helps.

BraMas

Just my .02 but stay away from welding the joints. Ths clamps they use now are just fine if you tighten them right. If you weld you have to cut the exhaust to get it off.

Metal Head

Some questions for you mlax:
Did you smell exhaust coming through the AC vents?
Was the exhaust problem there, whether you were driving or at idle, windows up or windows down?

So you think buying a new h-pipe with cats, and welding up everything will solve the problem?
Are saying weld the header collectors to the h-pipe, and welding the h-pipe to the mufflers?

I just want to make doubly sure before I shell out $390 for another pipe.

Thanks.