I have a '93 corvette, when I bought it one cat was broken up and in the muffler. So I just hollowed out the other cat.
Problem is it has, what I would consier, weird O2 sensor readings. The O2's are less than 12" away from the center of the cat, and the cat is one hollow chamber that it seems wouldn't hold a hot exhaust as well as a pipe.

It also has shorty headers because I couldn't find any stock manifolds that were not cracked.
The O2's read from the 900's to zero, fairly fast. The sweep shouldn't be that wide should it?

Anyone think getting rid of a hollow can approx 6-7" in diameter and 8" long and converting to heated O2's will help?