I ordered a 2.5" downpipe from mandrelexhaustsystems.com with a high flow magnaflow cat and simce then I've noticed an annoying raspy rattling noise when accelerating. Almost like a cross between an exhaust leak and rocks in a can sound, but not in either extreme. Is this normal? It seems to be emanating from the cat to rear flange area. Also as a note, the 2.5" downpipe is bolted to a 2.0" cat-back with no reducer. Could that be a possible cause?
Sounds like your exhaust system is loose. It could def be a hanger that is not secure or it may need to be welded up. Did a shop do it?
www.kronosperformance.com / 732-742-8837
Huh? Lol. I never really thought of that. The rear hanger keeps having a bolt come loose and rattle at idle. I wonder if that will be the problem, cause the noise was something that gradually got worse. But it still seemed to have been coming from the middle forward.
Also I installed the header, downpipe, and cat-back at my shop. everything was fine with the header and cat-back, but once the downpipe when on it sounded more raspy and eventually I got that rattle.
Did the core of the cat fall apart?
mitdr774 wrote:Did the core of the cat fall apart?
I would hope not, the thing is brand new.
Well it is not the hanger. The noise is definately from the downpipe, more specifcally upstream from the cat. The only thing there is the bung that got welded on for the wideband A/F gauge. Possible leak???
Also notice some discoloration in the piping. I know when new it was stainless steel looking, polished. Then after little use the turned golden. But some spots on the downpipe actually look purpleish-blue. What does that mean?
thats just from the heat 304 piping, did the exact same thing on my system
Well I found out that a layer of flex-piping inside the collector had broken off and twisted, restricting the exhaust and causing junk to fall into the cat. Sending it in under warrenty.
i have the same wierd problem, i did cat delete...i did not touch any hangers, just cut the cat out, put a straight put in, touched nothing else....now the whole thing shakes like the weight of the cat was there ballancing it out..gonna throw another hanger on it sometime this week
