Hello guys, I have search all day long and cant find an answer. So yesterday morning I was going to the store. It was roughly 34 degrees. I always warm the car up fully before moving. I got it and it started fine, idled up smooth then out of no where started cutting out. It now sounds like a ATV or Dirtbike. After it warmed up i revved it and it was cutting out with loud backfire and i shut it down. During the rev it shot a chuck of cermetric or something that can crushes into ash upon stepping on it. My buddy crawled under the car and said the cat was hot. I dont know if its a clogged cat or not. It ran awesome the day before and Ive never flooded it. Its an 2004 6-speed, 36,xxx miles. I bought it used in Jan. No issues what so ever just out of the blue. It get its redline daily. I only use 93 and I premix 6 oz to a full tank. Only thing i can think is a clogged cat. Others show symptoms of power loss at high RPM but it was fine til that morning. I just hope its nothing serious. My mods are K@N Drop in, dewalled airbox, HKS Hi power. Thanks again, I searched all day and cant find anything on the chuck of whatever, or the bad miss that shakes the car

 

BTW car is missing so bad it wont move... I'm going to order a midpipe if thats the problem, just doesnt make sense it would miss that bad with just a cat issue

 

sounds like your cat is toast. check it out but do it now. a bad ignition can cause a cat to fail which can waste your engine

 

You're cat is smoked!

 

op, were you getting misfires (flashing cel)?

 

all started at once this morning and the cel is flashing. I havent started it since bc i have read the cat would destroy the engine

 

I'm hoping its just the cat, Good reason for a BHR or Racing Beat DR midpipe, I'll try to gut it tomorrow just to see if its helped before i drop 400 on a midpipe

 

flashing cel means misfire which kills the cat which kills the engine. when was the ignition relpaced last? you need to fix the misfire and the cat issues

 

pics or ban! if its a ceramic, its the cat though

 

the CEL started flashing that morning when it started missing. it hasnt missed a beat since ive owned it.

 

Hello, the strata in your cat has broken up. There is a good chance that pieces of it are lodged in your exhaust or mufflers and will still be a problem after you install a midpipe. You might have to take your exhaust apart and try to shake the pieces out. If you hit on it you may be able to hear it rattle. Hopefully it was just the first piece to break off. Good luck.

 

99% sure its the cat

 

Yeah your cat clogging up can cause misfires due to back pressure caused by the clog. You did the right thing by shutting it down. Think you'll be fine once you replace/gut the cat, but yes, check the entire cat + back for debris.

 

Also check your intake for oil that was blown back due to the back pressure.

 

Okay well I took my exhaust off and got all the honeycomb out of it and it still will not idle and misses so bad it won't take off. I reset the battery and cleaned the maf and nothing it still won't run any suggestions

 

take out your plugs and take a snippet for us. Either they are fouled or you got bigger problems

 

+1. Check your plugs. If you haven't done coils, plugs and plug wires, now would be a good time.

 

I just wanna thank you all for the help. My plugs coils and wires came in today. I put them on and reset the battery and she runs like a top. Fouled plugs and all the coils had the white spots on the back. It doesn't look like the previous owner did any of the ignition. Again thank you all for the help. Means a ton.

 

glad its fixed but white spots on the coils dont mean ****