Z28barnett

Cat Self Gutted - Brick in the muffler???

I am doing a cam swap and an Opti replacement due to missfiring.

Tore the oil pan gasket, so I had to drop the Y-Pipe and Cat.

The cat is a magnaflow OEM fit that I put on about 6 years ago.

Thought I should check to see if the Cat was plugged due to missfire dumping raw fuel.

Nothing in the Cat, just a thin coat of carbon, brick is missing and assumed to be in the muffler. Muffler is OEM Chamber type. I have not pulled the muffler yet.

My question are:

1). Has anyone seen this before?

2). Will the muffler be full of chunks or powder?

3). If this happened to you, what did you do?

Thanks

Alan

94QuasarZ

Mt next step would be to pull the muffler and see if you've got anything stuck in there, good luck and hope you're able to diagnose this soon.

mzgp5x

Yes, happened to me.
App... 97ss 383-D1 MM6 trans.
Run slp short headers to a random Y single Mufflex with Spintech muffler.
Dual cats. One cat "de-gutted." Other cat OK.
Assuming due to FI exhaust pressure. There's alot of it.
Cat was about 5 to 6 years old.
Pushed the brick (or parts of it) into the cat-back 3 1/2" pipe.
Got stuck in the pipe. Took all exhaust down and cleaned up.
Replaced cats with (2) 2 1/2" straight pipes. Maybe I will go back to the cats later.
Loose brick pieces sounded like alot of bolts rattling around in there.
B.

Z28barnett

Thanks for the replys.

I didn't want to pull muffler and tail pipe, but I don't see much of a choice.
Plugged pipe could have helped cause power loss.

Metal Matrix cats - are they less likely to fail this way?

Anybody had good luck with Random Tech MM cats?