My old cat is blocked up so picked up a higher flow one to replace it with. Got the rear of the old cat free from tailpipe & muffler. Got the front of the cat free from the crossmember brace & took off the U bolt. Banged on cat with rubber mallet & even tried a come along until I was afraid of breaking the exhaust manifolds. No room to cut it off & have enough straight pipe to put a new cat on. I also do not own a torch of any kind. So anyone got any thing I should tried to get the old cat pulled off?

BTW the vehicle is a 85 S10 Blazer 4x4 with a 2.8

 

When it comes to exhaust pipes that are held together with an exhaust clamp (u-bolt & saddle), they can be a major pain to get apart. I would recommend finding someone with a small grinder and cut grooves in the cat's inlet pipe just deep enough to go through the cat and not into the y-pipe.

 

I will borrow a grinder from work. Thanks!

 

A thin cutoff blade will make the job easier and faster!

 

when i got my cat replaced i cut it off with a plasma cuter LOl . worked out great

 

Yup, backyard mechanic style - cut horizontal slices along it but not through the Y Pipe & get at the "slices" with a ball peen hammer & a cold chisel & PEEL it off the Y Pipe.
OR take a reciprocating saw, cut it off at the end of the cats tubing, get whatever you'll need for length of 2-1/2" from a muffler shop (I think thats the diameter) exhaust pipe, 2 extra bar & saddle clamps, have that muffler shop enlarge the pipe at the ends so the ID - interior diameter will fit over the OD - Outside diameter of the existing exhaust pipe. Clamp it all together. They'd probably enlarge the ends for nothing & the 4" or ? you may need might cost you $5.
If you have other transportation cut it out at the ends of the cat & head to a muffler shop.