I noticed my car making a funny noise today, almost like a broken exhaust hanger or something of that sort. The car has Kook Long tubes, with their catted y-pipe (Magnaflow cats). As I proceed to inspect the noise, It sounded like a busted cat, although the system is fairly new. I notice little "shavings" comming out the exhaust, what are these?

Shavings

I also noticed that one cat gets hot, and the other not so hot. Which one would be bad, the not so hot one? Im guessing the not so hot one would be the bad cat, because since there is nothing inside of it, it is not heating up. Any info would be greatly appreciated....

 

those "shavings" are parts of the inside of the cat, samething happened to me with one of my magnaflows cut it out and take it where u bought it they should give u a new one took like a week but got a new one free. from what i hear the mangaflows have this prob alot and need to be about 8 inches down the exhaust after the header collector to keep it from happening also have heard that the random tech doesnt have this prob so that might be somehting to look into. also if you have anykind of chambered exhaust your gonna have a fun time trying to get all the broken cat out of it with my LM it just went right out the pipes, big chunks too

 

well a lot of it flew out of my Borla Exhaust. I thought this was my cat. I will contact Kook Tomorrow, as they are using them in their y-pipe and header packages...Thanks! By the way, do you know which cat it could be? The one that is getting hot, or the not so hot one?

 

Definitely fragments of the honeycomb ceramic substrate that carries the catalyst.

Its coming out of the cat that is "cold". The catalyst promotes combustion of unburned HC's and CO, generating heat. The one that is working will be hotter than the one that is not working.