2002 Ford Focus

I recently had an " accident" on a freeway. As I was attempting to go around someone, I accidentally downshifted into a TOO LOW of a gear and sent my RPM's off the scale. The car over revved, and shut it self off (white smoke was seen comming out of the back of the car as well). I pulled over and did a quick general inspection and noticed my CAT glowing bright red. The car still runs but I have the following OBDII codes: P0141 and P1131. The gas mileage has gone down considerably, horsepower and torque is now suspect and when the engine is cold, it hesitates and misfires. After it warms up a bit, it drives fine. What gives? Could the O2 sensors be causing this problem or is this privvy to something more serious (bent valve). HELP!
May 14, 2007.

P0141 HO2S Heater Circuit Bank 1 Sensor 2
DTC Description VIN Digits
Manufacturer 3
Division 4
Body 5
Series 8
Engine 10
P1131 HO2S Circuit Low Variance Bank 1 Sensor 2 G C X
P1131 Lack Of HO2S11 Switches - Sensor Indicates Lean M
Do a compression test, then rap on the converter to see if it broke up. Any rapping in the engine?

May 14, 2007.
No. No tapping or " slapping" noises that I can hear.

May 14, 2007.