Do both banks use the same sensor or are they 2 different part# (post cat). After looking on courtesyparts.com I'm slightly confused, see links.

This one bank 2 sensor 2
http://www.courtesyparts.com/22690na...8-p-13712.html

And this Bank 1, Sensor 2 and/or Bank 1, Sensor 1 (I think sensor 1 is a typo)
http://www.courtesyparts.com/22690n-...4_715_743_747&

Also when I looked at autozone the bosch sensors are different parts for each side with one being more expensive. Any incite would be helpful.

 

With the earlier 350Z and Infiniti G35 the two front and two rear O2 sensors are different part numbers, however i am not sure if they are actually different sensors, although i suspect they are, the rear (cat) sensors are basically there to monitor cat function and whether they supply an extended frequency signal or are just monitored differently by the ECU I'm not sure.