mlcrycc

Anyone ever have one of thier stock cats fail? I am trying to diagnose a very strange rattling sound, that is not constant, and seems to rear it's head moreso when the car is warmed up, and being driven agressively. Seems to be more pronounced when revs are high, and back pressure is allowed to build, i.e. high rev then decel.......

Anyone have one go out? Associated sound??


Thx,
Mike

fullboogie

I once had one break apart (internally) on my 93, and it was just as you described - an intermittent rattling that was hard to diagnose. Get a rubber mallet and tap on the bottom of the converter (lightly). You may find the culprit.

kingsofcrunk

Does it only happen when the car is cold? Mine does the same thing, and it's really loud and annoying when it does it. It progresses the more gas you give it. Found out it's the heat shield in between the cat and the actual car. It's made out of really flimsy metal than you can bend just by touching it. Other people had the same problem.