I too had a Dodge D50 (Mitsubishi) with a plugged cat converter. It ran with all plugs, but would barely make it up a hill to work. I found the plugged converter and decided to bang it out as you did. Ran great. I could only get a new converter from the dealer. It was big bucks. It was time for emissions test so thought, what the heck. Might as well give it a go. Guess what? It passed and I don't mean by just a little either. It passed easily. So I said screw it. Never did replace it. Looked legal from the outside too.
Dennis
