I have read regarding this issue previously, and im aware of rattleing issues with the cats. But i am haveing a problem in the back end of the exhaust setup. I am running a stock exhaust,a nd HFC. Only change to the stock is that i cut out the resonater and replaced it with an aftermarket one. I think this may be the problem. The car is very raspy right now, and when it revs back down to idle i get a rattle around 3k rpm's. I am taking into a shop tomoro to possibly remove the resonater and install the stock one again, or install a different (bigger) resonater.

^^^ any suggestions please?


and also, question for those who have installed crawford cats....did your installer use the stock brace on the new cats? and the gaskets? my installer told me it wasnt needed and didnt use them, could this be a problem?

 

happened to crawford cats also. went away after the retainer bracket was mounted.

 

loosen everything and retighten from end to front to rid the rattles

 

what retainer bracket? the stock one? How was it attached to the new cats, my installer said he didnt see a way too.

And also, does anyone have stock exhaust with crawford cats, if so do you have any rasp at all?

 

I've had that rattle for a year now. It happened when I had kinetix cats on my stock sedan exhaust, as well as crawford cats with the same exhaust. It's almost a metallic hiss.

I put it on a lift, and it sounded like it was coming from one of the flex sections on the stock ypipe. I even got an extra OEM ypipe for replacement, but never put it on.

I then got a stillen sedan exhaust, which replaces the ypipe with an xpipe(no flex sections). To my surprise, the hiss was still there. On the lift, it sounded like it was coming from the middle of the xpipe.

I eventually put my stock cats back on, and the sound was still there.

I've just learned to live with it.

 

I went ahead and had my stock resonater installed again, rattle went away.....now my rear bumper is vibrating and causing a rattle at 2k rpm's =\

 

ahhhh this rattle is so annoying! 2am....turn on the car, and it rattles as the rpm's fall from 2kish down to 1.4ish....it dies down under 1k =\ i need to find a way to fix it.....think its best to just wait until i isntall my exhaust and see if its gonna go away?

I asked a shop about isntalling the bracket from stock, but they said they dont find a way to mount that.

 

an engine dampener will get rid of the rattles caused by hfc's

 

i have that and i still have the rattles...

 

ok, i just spoke to doug and he mentioned the bracket is supposed to be installed - and it is attatched toi the transmission bracket?.....i really wish i could go udner there my self to see whats down there and how everything works.

The shop said they didnt see anyplace to mount the bracket........ can anyone confirm this is the bracket that should be mounted?

 

you know what is funny I just took my car into the dealer because on my car it sounded like it was comming from the tranny. Found out it is in the Y-pipe. I think that it is comming from the backpressure and something in that Y-pipe. I am going to pull my Y-pipe off maybe tomorrow and find out what it is. I will let you know

 

thanks, do you have crawford cats? if so can you please take a pic of your install? im going to be checking under there myself sometime this week.

 

bump for help!

 

yo...samething happened to me when i installed my HKS Dual Ti Catback...
i don't have HFC yet...but just right after i got my catback installed i started to get that rattle in between 1.4~1.7 rpm... this is really annoying...
i'm gonna take it to my friend's shop next week...i'm gonna find out what it is...

 

Did anyone figure out what's causing this? I get the rattle around 3K - 3.5K RPMs while accelerating. I was considering replacing the resonators on my Stillen cat-back system with the same (but new) ones.

TIA,
B