Question about new exhaust vibration

[fox-gt]

I installed a new H-pipe and Catback on my 93 GT. Sometimes when I take off it vibrates under the floor plan (around the transmission). I had the local muffler shop check it out and they say everything is clear and tight. I noticed when I took off the stock H-pipe the hangers behind the cats were cut off, it was only supported by the headers and muffler pipes. The old setup didn't vibrate at all (althought it had a major leak between the headers and H-pipe). When in neutral or park, I can give it gas and it usually doesn't vibrate, only when I take off in drive, and almost always when I punch it. (it is an automatic)

Anything I can check or any ideas on what this could be?

 

[HISSIN50]

Is the exhaust hitting anything (ebrake bracket, DS, frame rails on the side, etc)?

If it vibes while sitting still, if you raise the idle a hair, does the vibe go away?

Good luck.

 

[fox-gt]

In park or neutral, no vibration. In park or neutral and push the accelerator, no vibration. It mainly vibrates when I put it in drive and take off (and it is not consistent). I will get it back on the ramps this weekend. Everything seemed tight though, not much room for stuff to move around.

 

[HISSIN50]

It seems to me that it is a dynamic issue then.

I would make sure the DS is not rubbing. My DS has score marks where the stock H rubs. Getting it up in the air sounds good.

Good luck.

 

[IntenseBlue]

My friend Michael had a similar, if not the same problem you're having. It was a BBK Xpipe. The hangers were vibrating agianst something on the transmission. Solution: cut them babies off. Didn't hurt anything and the problem went away.

 

[fox-gt]

My friend Michael had a similar, if not the same problem you're having. It was a BBK Xpipe. The hangers were vibrating agianst something on the transmission. Solution: cut them babies off. Didn't hurt anything and the problem went away.

Mine is a BBK H-pipe. I think that might be the problem, the old stock h-pipe had them cut off (from the previous owner). If worst came to worst, they could be welded back on right?

 

[IntenseBlue]

I actually meant to add that in there. Yeah, if that isn't it, then they can be welded right back.

 

[redterror302]

Before you go cutting everything off, make sure you double check everything. I've had many different vibrations coming from my exhaust.

One was a o2 sensor that backed out a bit. Another was the smog pump tube was hitting the h-pipe only while driving. Also, if the tailpipes weren't welded in, check to make sure they didn't shift and are now hitting the frame rail above the axle.

Check to make sure everything is tight and in the right place before cutting anything. If all else fails, maybe the hangars do need to be cut(don't have experience with AOD's).