I recently purchased the KOOKS full exhaust kit from Brenspeed. They forgot to ask whether I had a manual or automatic, but when I fould out the only MAJOR difference was the amount of 02 sensor extensions, I didn't really mind, and they sent them next-day-air, what a good company... now I'm starting to think the 02 sensor connections may have been different also.
ANYWAY
I get this weird vibrating noise when I accellerate to about 2-2500 rpm's. Slow accelleration doesn't do it but moderate to WOT does. I thought that maybe the 02 sensors on the cats were hitting the heat shields but I don't think the Exhaust moves an inch (amount of clearance I have) from moderate throttling. The car doesn't do it in neutral only when the tranny is engaged. Any help pn this would be GREATLY appreciated. The noise is annoying the S*** outta me and if I bring it to Ford, I'm pretty sure they're gonna charge me b/c it's more than likely related to the exhaust. I can't remove the heat shield for obvious reasons, but I bent it a little and it didn't help, so I doubt that was the problem.

 

Mine did that when I put on my x-pipe. the hangers in the middle of the car were rubbing against the bolt head. I just bent the hanger down and it went away. Try that.

 

Thanks alot... I hope it works

 

how much of a difference in performance did you notice? did you have the car retuned for them, or just slapped them on (prolly like a 6 hour slap on) and drove it?

 

Yeah take a look at your exhaust hangers.

I had a similar problem with the vibration. It happened because my driver side cat back pipe wasn't seated totally up against the x pipe. That caused the hanger on my muffler to hit the frame of the car at certain RPM.

 

This install will probably be the most annoying one you will do. Especially if you don't have a lift. To get everything on and snug it took me about 12 hours. The instructions they give are HORRIBLE!!! So alot of the time is spent figuring it out yourself. I noticed a slight increase in performance, a larger increase in gas mileage 4-5 more mpg. After I do the mufflers I can expect 20 more hp and 3 more mpg. They sound sweet, but they are not rediculus, so you won't get the "wrong" kind of attention. Brenspeed sent me a tune cause I asked, it's not necessary but your car will run a little lean without it.

 

it was the hangar on the X-Pipe... I moved it back and it's not rubbing on the tranny crossmember nemore.