Collapsed Cat

[mystery_kid]

recently i put an r34 gt-t turbo in my r32gts-t

anyway since then i've had this odd sounds, it kind of sounds like it could be an exhaust leak or something rattling even

it loudest from under the passenger side door, but you can hear it a bit in the engine bay

at first i thought it was an exhaust leak from the joint in the exhaust between the front pipe and cat

i can confidently say that isn't the problem after replacing the gasket and bolts and what not

at first i instantly thought it was an exhaust leak from a turbo gasket but i have been over these and they certainly do no appear to be leaking all the nuts and bolts are done up tight the head to exhaust mani gasket has also been replaced a bit less than a year ago. (all gaskets were replaced with legit nissan items)

this sound is driving me insane, i'm now left thinking has my cat collapsed? could shit be rattling around in side of it because it sounds like it when i lay under the car

the cat isn't anything special it's been welded onto the exhaust on the outlet side of it because the exhaust is 3.5" and the car is either stock or something but it's 3"

is it even possible to have something rattling around in a cat? i'll admit i don't really know what goes into one

Thanks

Dan

[PM-R33]

Cats can break apart and rattle if they are ceramic style cat like the stock ones. After market metal ones usually just collapse and weld them selves together from the heat.

Symptoms usually are a different exhaust note (if you can notice it) and a loss in power (depending on how collapsed it is). Really only way to be sure is pulling it off and having a look.

[mystery_kid]

i'm pretty sure this isn't a metal cat and i can't pull it off because it's welded to the back half of the exhaust :\

[mystery_kid]

also as far as losing power that goes with a cat dying etc, it does come on boost fairly late i realise it's a bigger turbo but it's dead set not full boosting until around 4500rpm for 0.8bar

[HEKT1K]

that sounds excessive for a stock turbo (even on a 20). maybe cut the cat off. if it's not collapsed, just get some flanges welded back on, shouldn't be too difficult or expensive