i have been hearing this rattling sounds lately when i drive, it sounds like metal hitting. it is only when i hit a bump. form listening it sounds like it is comeing from around the cat. question is if my cat is bad will it be all broken up in side and be makeing this noise?
the only ither thing i could see is the heat sheild above the cat taht is connect to the car may be a little loose. haven't had he time to get under and look yet

 

If it is rattling from the cat area, and its not a heat shield, its the cat. A rattling cat is a bad cat. Find out what caused it to go, unless it just went because of old age.

 

i tbetter not have went because of old age. i have only had it for maybe a month. what are some reasons that a cat would go bad?

 

Try tapping on the cat with something, if it rattles, its the cat and check the heat shield too. Maybe it was just defective, prob under warranty though.

 

Check the heat shield on the car that it isn't hitting the cat. Make sure the spot welds on the cat heat shield are still good. I had a couple customers have this problem of the spot welds breaking and the heat shield rattling so I now tack weld down each side of the cat and no one to my knowledge has had another problem. I have a picture of the spot welds that I did for a customer after they had broke if someone wants to post it.

If the above is OK, hit the bottom of the cat with your fist (hot!) and if you hear a clunking noise - the guts are bad. If that's the case check your date code on the bottom of the cat and see if it's 09/99.