Thanks guys. I got a new cat on Friday and put it in today. I did not bypass the O2 sensor, I simply replaced the entire cat asembly from the exhaust manifold back to the resonator (Maremont direct replacement - $201 at AutoZone). The new one was configured to eliminate the big "U" for the O2 sensor which has to help with flow. This car is mostly for transportation, so I wasn't looking to go high performance, just restore it to good operating condition.

The issues are all completely gone. I don't know when it last accelerated as good as it does now. On hard accel, it winds over 6000 rpm and the trans shifts perfectly, and if I let it, it spins the tires on the 1-2 shift.

Thanks again for your help.