New Exhaust System.......problem

[VTI-RRR]

hey guys just a qiuck question got a new full system 2.5", hiflow cat and 4-1 headers......

its been a week now and a big ratteling noies is coming from da cat what caould it be??? cant get rid of the noies........

its bad pealses help...

thankz bobby

[nakz]

i hate noises... check the screw.??

[VTI-RRR]

nah its welded on to the headers

[bennjamin]

did you check the header hanger isnt touching ? ( located under the oil filter /collector area - its where teh stock header joins to with 2 x nuts)

IF this is left on , it can touch the collector and make noise. Easy to take off

[vinnY]

does it sound like rice shaken inside a tin can?
probably little bits of the welds broken off and are just rattling around in your exhaust
good luck getting it out though

[90LAN]

your new exhaust mite be hitting the heat shields underneath becos of the bigger diameter exhaust ?
do u have a flex pipe welded onto your cat - headers
if not expect it to crack in the future
best to of have kept the donut flange

[VTI-RRR]

i do have a flexi pipe join and i jucked the car up to see if the new bigger exhaust is touching enywhere nogo there ither. its comming form the cat area but still dont know what it exactly is.........

thanks fror the help

[VTI-RRR]

the noise is very bad now its sounds like my car is gonna fall apart....
now i relies that it may be little bits of broken weld......

dont want to drive it its dat bad should i take it back the the exhaust shop??

[vinnY]

definately have them take a look again, they'll probably try to blame your cat dying at first(unless its a metal one)

when i had mine cut apart i tilted the pipe and all the metal bits came out and the cat was fine

[Joeyboy]

I hope the exhaust shop is close to where the car is. Just get it in there as soon as u can and make sure they fix the problem b4 u drive off again! Just make sure that they dont try to blame it on u. You paid to get it done properly and u deserve to get something that works. Just make them feel bad about it and tell them that u paid good money and u expect it to be fine. Hopefully they'll fix it for u for free. Have u still got the receipt?

[94vtirozguy]

i would guess it would be something rubbing against your heat shield.

just jack up car, and tap out the heat shielding a little

[ECU-MAN]

sometimes the pipe hits the gear shifter as well,

do you get the rattle in all gears

[VTI-RRR]

it only happens when i come off the excellarator and whan its on idol you cant hear it when ur driving, just a bit but very bad when shifting down to stop....

[traumatized]

i'd take it back to the exhaust shop asap, as the longer you wait the more reason the shop will deny their at fault and blame it on you or something.

[Limbo]

sounds like it might be a faulty Cat. There was a bad batch a while ago cos i know of alot of them coming back whilst i was at the exhaust shop. Your exhaust shop should be able to tell you the fault for no charge & replace the cat if its their fault

[Joeyboy]

it only happens when i come off the excellarator and whan its on idol you cant hear it when ur driving, just a bit but very bad when shifting down to stop....

hmm.....i had a similar incident not so long ago. it was like a grinding/rattle sound. And the muffler guy found out that a nut in the manifold has come loose and fell off. They just replaced the nut and its all good now.

[vinnY]

it only gets worse because on down shifting it makes the exhaust shake slightly causing the sound, it'll happen whenever you downshift without rev matching
try holding the revs between 1500-1800rpm and i bet somewhere between that range you'll hear it rattle

also if you're okay with hopping under the car, jab the cat to see if it rattles. if it does then it might be a failed cat.

this is my experience with a custom exhausts and failed resonator, but it shouldn't be too different to yours

[VTI-RRR]

im going to the shop 2moror to get it checked....
its looking like i need to get a new 1
but 1 problem i supplyed the cat..
and its from queensland i call the dude i got it of and said they will replcae it with a new 1...
but i need to send my 1 back so they can have a look at it...

for now what should i run???
straight pipe(illegal)
or stock cat if it can fit...

[IEVAQ8]

hey bobby, i told you to poay a little extra and get alan at blitz custome exhaust to supplyt and fit the cat.

you know its your f*k up...lol
good luck man....i hope its ready fro the track tomorrow

[BlitZ]

good luck man....i hope its ready fro the track tomorrow

open headers for track.:thumbsup:

no zorst no problem

[aaronng]

open headers for track.:thumbsup:

no zorst no problem

WRONG. Not at a track like Winton Raceway. You need an exhaust that limits noise to 95dB at 30 meters from the track edge.
http://www.wintonmotorraceway.com.au/home/index.php?option=com_content&task=view&id=52&Itemid=25