Cat Converter - trouble removing

Original cat converter (1985) replacement is long overdue. I have successfully completed the removal of every required nut, bolt, and clamp. There are no welds. The cat is loose and wobbles on the exhaust pipe at the engine side. That's the good news. The bad news is that this connection had a "U-clamp" on it, which though successfully removed, has left a crimp around the circumference of the cat pipe and the exhaust pipe inside the cat pipe. This crimp is preventing me from removing the cat by means of sliding the cat toward the rear of the truck and off the exhaust pipe. In the very limited working space available I have pounded the loose connection with hammer and chisel in an attempt to move the cat off the exhaust pipe. The crimp is preventing any movement though the joint remains loose. There is no room to use a hack saw, and I don't know which portion I'd want to cut even if I could.

Please, any helpful ideas ?
Thanks kindly.

Phil Mac

What a muffler shop does is heat the joint and slip the cat out while it's hot and more flexable.
Since you don't have that option I'd sugest using a sawzall (reciprocating saw) to cut the cat off. You can find one at any rental shop for probably 5 - 10 dollars a day. They require far less room than a hack saw.

After you cut the cat off just use a chisle or even a screw driver to remove the remaining piece.

Also rent a Tail pipe expander to spread the old flange back to the proper shape for the easiest replacement I can buy one of these for 25.00 canadian so it should be cheap to rent