phox's list is correct except that some '94 2nd gens didn't have a cat.

Cats don't work on diesels for long before they clog, about 80k max on a 2nd gen. Power loss and high egts are the result.

A good buddy who is a mechanic for large bus fleet told me the cats on their 12 valve CTD equipped buses were clogging about every three months. Cummins was replacing them under warranty until the 24 valve engine came out. Cummins then replaced all the 12 valve engines with 24s for free, it was cheaper for them to hand out new engines than pay $900 a pop for new cats.

Now they replace lift pumps.

 

Some may not have, but alot of 94 trucks did have cats. My friend and I "fixed" the cat on both of our trucks. He through his outside while I took the hart out of mine. (in case of a emmisions test while travelling to Canada). just my .002

 

yep. My '94 had a cat that ran away.

 

Just to add more fun to the mix, any vehicle that was certified as 5 state emissions legal may also have a cat. Those states are California, Vermont, Massachusetts, Maine, and New York.

I know of at least one person on another board that has the HPCR SO equipped truck that has a cat on it. He's from Boston. Took a while to figure out what he had!

Matt

 

My 1996 HAD a cat and also has the EGR, doesn't seem to work with out vacuum line hooked up.

 

i am happy with mine. no cat, no egr.. life is good

 

I owned an early 98.5 24v. No cat.