Catalytic converter
 

My car is not passing smog. I think it the Catalytic converter.I took it off to see if i could tell if was bad and small rocks or sand came out.A friend say it's bad.That's what left from the inside.Since i live in california it will cost $275 for a new one.I want to make sure it's bad.

rocks and sand are not suppose to come out of your cat im guessing thats the problem.