8a8mfh

While I had my exhaust off doing some work to my 93 I noticed the drivers side cat was empty. No problem just though someone hollowed it out. But while handling the exhaust assembly I could hear rattling so I stood it up and shook some small pieces of cat out.
Is this common? Think it'll clog a muffler?
I have to put my money elsewhere on the car for now. Cant replace the mufflers.

gerardvg

Yes it happens.

I found that my cat was hollow, the guts disintigrated and just left small pieces that i shook out of the mufflers.
Most small pieces would have worked their way thru the exhaust system, they must be those damned small rocks that chip our bumpers windshield from time to time when thraveling behind cars.

Just rev the car and have someone feel there is plenty of exhaust flow from each muffler tip, if both sides are the same you will be able to forget about it .

DUB

Ozzstar

A simple backpressure test can be done to be certain. By removing an O2 sensor and screw in place an exhaust back pressure gauge. Should be around 1lb of pressure or less, anything more like 2+lbs would determine there is a blockage. Then simply reinstall the oxygen sensor after the diagnosis. Each side (left and right) exhaust banks should be done individually.

leesvet

yep. happens a LOT.

The pre-cats break and send the trash to plug up the main, or the main breaks apart and plugs up the mufflers. I had one break and clog the mufflers so badly that it would not run over 30 mph....the exhaust could not get out ! had to literally take the system OFF the car, and beat the chunks out of the mufflers and even then, there were some that were so far stuffed in that they would not come out. Those muffs eventually had to be tossed.....
I'd lose the pre-cats and live with a GOOD main cat and the smog guys will never know the difference. They used pre-cats on some yr models, others no. Then next yr they were back. As long as a big main is sitting there to pass visual, they don't know or care as long as it passes the sniff.,..They won't even look unless given a reason. They don't like laying on the floor anymore than we do.

8a8mfh

Guess I'll just run it. I has 118,000 on it, who knows how long it's been like this. I beat it around quite a bit and didn't hear much, especially after the few chunks fell out.