vibration in passenger floorboard, goes away with use of gas pedal

Lately ive noticed that once the jeep "warms up" or after driving for a little while, when i come to a stop there is a vibration under my feet and passengers feet that comes to life. sometimes when i shift into nuetral the vibration will go away.

also as soon as i touch the gas pedal, the vibration goes away immediately. so if im sitting at a light and the vibration starts i can barely put my foot on the pedal and the vibration goes away.

what is this? just based on where the sounds coming from i was leaning towards the flex plate/starter, but i really dont know

what do you think?

-Brendan

Mine did the same thing for the longest time, finally went looking for the noise and it was the aluminum heat shield on top of the catalytic converter. Hope that helps

hmm, im not sure. i dont have a cat. i think it could be the exhaust tapping up against the TnT Belly pan, but im not sure

Mine also had a similar vibration. It was my rigged up straight exhaust pipe (where the cat used to be) vibrating on the crossmember. Took it to an exhaust shop and had them tack up a exhaust hanger to get it off the x-member, worked great.

...if its not that, its worth checking the motor and trans mounts. Likely not the cause, but it wouldn't hurt to make sure they are good.

Not sure why you would want to remove your cat in the first place.. but I wont start preaching, no one wants to hear that and if you think running no-cat gives better performance, you should do some research.

Regardless: count me in as another vote for exhaust. My exhaust was loose and it would rattle like no tomorrow and hit the x-member and several other locations. Just add a hanger or 2 where you are having problems (I did my own hangers rather than bringing it to a shop). Can pick one up at autozone or where-ever for pretty cheap. Then the hard part is finding a mounting location for it... Though if your Jeep is still in nice condition a shop would probably be best, I was lazy and ended up with a bolt through my floor pan

Just to clear this out, my cat was gutted by the previous owner. Not sure of the reasonings, but it was gone when I bought it. It does make it sound awesome with straight pipes into a Cherry Bomb glasspack

Well....as awesome as a 4.0 is going to sound lol