hey guys just wondering if anyone can help me i put headers, high flow cat, and cat back exhaust on my car but when i hit about 3 to 3 and a half rpm's a little rattle sound comes from somewhere and i don't know where i was thinking it was my exhaust manifold gasket cuz i used the stock one so can anyone help me out thanks

 

my car does the same thing but it goes away once it warms up, mine sounds like its comming from the cat area. Its more than likely an exaust leak.

 

eaither exhuast leak, the pipe bouncing off your rear fender, or the cat vibrating off the under carraige.

 

I get rattle around 2k rpm from the catalytic converter hitting the underbody of the car. I am about to take it back off and put on the test pipe.

 

check your heat shields all the way back and make
sure the catback isn't rubbing anywhere.

 

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SKDRCR &raquo;</TD></TR><TR><TD CLASS="quote">check your heat shields all the way back and make
sure the catback isn't rubbing anywhere.</TD></TR></TABLE>

yup thats what it more than likely is. sometimes when your putting new **** on the sheild will get bent toward the piping

 

id say heat shield..
the guys who installed your exhaust probably hit it and broke one of the corners holding it up..
id get that checked out by the guys who installed it..
if it was an older exhaust would prob be the cat or heat shield.. but since new exhaust .. most likely your heat shield id say... honda's are notorious for that.. can be removed but not tooo safe.. (acc to the gv't .. can catch on fire and stuff) most people secure or remove it once it becomes loose....

 

would/could it make a rattling noise if it comes in contact with the heat shield even if the heat shield is secure? I guess what i'm getting at is if the CAT rests against the heat shield b/c its tight against the bottom of the car, would it still rattle? I'm guessing yes, just not as loud/high pitched?

I'm pretty sure my heat shield is secure, but i get a similar noise from 2.5k-3k. However, i also had to heat my flange and beat the bolts out with a hammer, so i was thinking i prolly bent the flange in the process just enough for a leak. I'll know for sure when my hi-flow cat OR resonated test pipe gets here.

 

I think it is the mounting bracket on the header's downpipe that monts to the block. If not that, then I think it is the exhaust hitting the metal heatsheild that runs throughout the length of the car.