My catalitic converter has been rattling like crazy lately so I guess it's time for a new one. Does anyone know the inlet/outlet diameter and lenth of the stock cat on a 3.4? I remember people saying catco is cheaper than the rest, anyone know how much a catco for a 3.4 costs?

Thanks.

 

There really isn't any specific one, they are all universal, so you just find the one the fits closest - the diameter and length are pretty much up to your choice. Almost anything is available.

But rattling may not mean its bad. (although yours' may very well be) There is a heat sheild located above it, and down the I-pipe about another 2 to 3 feet down. Mine were rattling so I removed them. You don't really need them, since the exhaust clearance from the body is near two inches. Only about 1/2 inch do you need to think about heat shields. GM likes to go overkill in the most profound and senseless ways. Check the simple things first.

But performance wise, a high flow cat will help and last longer than the stocker. May be a wise choice to swap now, or in the near future along with the purchase of a Cat-back exhaust, just do it all in one fail swipe.

Measure your cat's length (measure width too but just keep that handy - shouldn't be essential) and just match that up with one in the catalog. In either stock diameter, or if you plan to run a 2.75 or 3" exhaust, then you may want to get a 3" cat now, so that later on your 3" exhaust will bolt right up, and your cat won't impeded the flow.