96 Camry catalyst and transmission problems

I have a 96 Toyota Camry with 140k miles...

The check engine light came on so I went to Autozone to get codes read. The code said "Catalyst Efficiency Below Threshold (bank 2)" not sure of code number, but I've read that this could just mean that the O2 sensor is bad. How do I check and see if the O2 sensor is bad or the actual catalyic convertor needs replacing? Do I have to check both o2 or just the passenger/driver side (im guessing bank 2 means passenger)

Also, I've not had my light rechecked since I have had this new problem. My transmission hard shifts and leaks Transmission Fluid profusely (like a qt ever week).. It sometimes hangs in neutral when I shift up but only after the fluid is all gone. Is this just the transmission seal gone bad? Suggestion/Help would be greatly appreciated!

The way to test your cat. converter is to compare the output waveforms of the sensor 2 (after the cat. converter) with the waveforms of the sensor 1 before the cat. converter (you have two sensor 1, bank 1 and bank 2, and only one sensor 2). The waveform of the sensor 2 should be longer in period and lower in amplitude than that of either of the sensor 1s. If the output waveform of the sensor 2 is the same as that of the sensor 1, then the cat. converter is bad. If the waveform of the sensor 2 is out of spec, then the sensor 2 is bad and has to be replaced.

The easy solution is replace the sensor 2. It is most likely to be the problem. Make sure you get the correct sensor by getting a part number from Toyota.

http://www.autoshop101.com/forms/h37.pdf

Thanks a lot for the info about the catalytic convertor problem.

But does anyone have any information about the transmission... It leaks fluid (about a qt ever week or week and a half). I'm thinking its the seal but not sure. If so, about how much do these seals run and is there a specific type of seal...

Thanks a lot