I recently installed a Comptech cat-back and the buzzing start..I had a GReddy EVO II and i had no problems with it..What could cause this rattle? I have the stock header and cat...TIA.

 

same w/ me, i haven't check it out yet, but my apexi world sport just started rattling, i think its the heat shield though, on the center pipe.

 

SAME WITH ME MY N1 ONE RATTLES CUZ OF MY CONTROL ARM BUT I JUST CUT ONE EDGE OF MY HANGER SO IT SITS LOWER

 

Same problem here, never happened at first then just progressively got worse. it "buzzes" at 2100, then stops then again at 3100 then stops. Only at those 2 points...

I checked to see if maybe it was rubbing against anything...nope
Checked to see if maybe the bolts were loose...nope

 

i already took out both of my heatshields and it still rattle...its very annoying..

 

greddy exhaust is rattling against my frame its really annoying

 

Check the connection between the header collector and the exhaust or cat.

 

anyone else with a solution to our problems?

 

bump...

 

i had a s2 exhaust rattle on the last hanger against the rear bumper frame, i just cut down the hanger, never had a prob after that

 

It is definitely rattling against something. My suggestion is to buy some exhaust tunnel sheilding from DEI (thermal stuff) and put it anywhere that the exhaust comes close to frame/car. This way it wont rattle.

The stuff is self adhesive on one side and it can withstand heat up to like 1700F.

I used this where my exhaust rattles and now it doesn't. I also used it on the underside of my hood cause my full race mani was starting to ruin my paint.

 

one quick question..when i installed the new Comptech cat-back i did not have the gasket that goes right after the cat...the one that is triangular...could that be causing the exahust leek/rattle? do i need it?

 

ya, its a good idea to have it cuz then the pipes wont rust together as fast..i think. and its shouldnt cause teh rattling if they are tightly bolted together, but just like jack up the car and have a friend rav it, and try to pin point where teh rattling is coming from. Also, are u running a silencer?

 

it could also be a bad set up...not to diss or anything but it could be rattling against your rear bumper or control arms or even body....same thing happened to me. make sure the exhaust doesnt have the ability to touch the car...

 

I prolly would have had the same problem but I removed my heat shield, did a little sheet metal work and the catback never came close to it.

 

check your bumper

thats where mine rattles, but generally at idle...

just cause it aint touching when you look at it doesnt mean it aint touching when your reving to that rpm

 

well im 100% sure it not touching anything..like bumper or heatshieds...sound comes from around the cat area...

 

IT is possible that the heat from the cat is warming up the heatshield above it, attached to the car and the heatshield itself is rattling cause its flimsy metal.

Try letting the car warm up and as others said, rev it up a few times and get the rattle to happen. Then pinpoint where it is.

I'm willing to be it is a heatshield itself getting warm and rattling, but only after the car warms up.

 

Had the same problem. Two culprits:
Heat shield was rattling. I removed that.
Short shifter and linkage would hit my exhaust too.
BTW, I have a 2.5" Greddy PE exhaust.

 

I have already removed both of the heatshields..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chowmien &raquo;</TD></TR><TR><TD CLASS="quote">Check the connection between the header collector and the exhaust or cat.</TD></TR></TABLE> The gasket would help.

 

I am also having a similar rattling sound at around 3500rpm right after I installed my apexi ws2 catback. I pretty much pinpointed the sound to be the heat shield around the cat which I tried to take off but had no luck. The reason I knew it was the heat shield is because when the car was cooled down I banged on it and it made a rattling sound. I might need some airtools to get those rusted bolts off but the sound isn't as bad when it's hot.

 

Do you have a short shifter? It may be hitting the piping.

 

Like I said earlier, same problem. No solution w/o removing the short shifter. And that's not an option

 

i had a terrible buzzing noise coming from either the cat or resonator for the longest time. the buzzing slowly moved to the muffler and then one day it just quit. well it didn't quit, it just greatly quieted down. i took my center console out (to check the broken factory radio stuffed in my dash for keyless entry) and you can still hear the buzzing coming from either the resonator or cat, but it's just a faint buzzing now. really wierd. i've replaced the resonator, next is the cat. oh, and i'm definitely gonna do the thermal wrap.