This peculiar noise started at the same time I lost power.

[StevetS]

Hey everyone, I’m wondering if you can help me identify this rattling noise under my car.

I put on the Edelbrock supercharger about a month ago and it’s been running absolutely phenomenally lately. I have upgraded injectors and a fuel pump as well as a over pipe back exhaust from counterspace garage. I drove to the gym yesterday and the car felt perfect, however, when I drove back from the gym, it felt like the car had no supercharger at all, it felt very laggy and under powered.

I drove the car this morning to check if the symptoms were still there, and they came back more when the car warmed up, which makes me think it’s coil packs, however, this sound started when I was leaving the gym, so the car essentially lost power, and this noise started on the same trip, which is very peculiar. I’m pretty familiar with cars and mechanical issues, but I haven’t heard this noise before I do have the stock exhaust manifold on the car right now, so maybe it has something to do with that. I also have an Exedy OEM clutch on the car as well which I was going to replace when it died but the noise kind of sounds like it’s coming from the clutch area or from the exhaust manifold area but I’m not sure. The sound is a lot more noticeable when getting low to the ground next to the car than it is from the engine bay.

Any help identifying this noise would be greatly appreciated.

https://player.vimeo.com/video/815552140?h=c7793d4bd8

[tomm.brz]

i think it s a cat that got destroyed by yhe sound of it....
is the sound rpm-related? or sounds always random and rattling like amarmbles in the exhaust?
Since you have negative trims and super rich afr... i would lean in this direction of the cat and maybe put down header and front pipe to check them..
coil pack would give at least some error or misfire in logs

sound similar and was the cat

[tomm.brz]

Hit the exhaust manifold and front pipe with a rubber hummer...

if it chunks it s the cat

[StevetS]

Originally Posted by tomm.brz

i think it s a cat that got destroyed by yhe sound of it....
is the sound rpm-related? or sounds always random and rattling like amarmbles in the exhaust?
Since you have negative trims and super rich afr... i would lean in this direction of the cat and maybe put down header and front pipe to check them..
coil pack would give at least some error or misfire in logs

sound similar and was the cat

100% that is the exact same noise I am hearing. Very interesting, at least now I know what a failed catalytic converter sounds like. You were dead on again! I am looking for a used set of headers locally and if I can’t find a decent deal. I will buy a new set.

[tomm.brz]

first try to understand if i m really right
and if it s the one in the header or the one in the front pipe that detached