i'm getting code P0146 - O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 3). is this the post-cat O2, and would a denso sensor be the smart choice?

 

got a loaner O2 socket set, going to swap the pre and post-cat sensors.

 

swapped the sensors - which was no small task. the post-cat sensor looked original, had to torch the exhuast pipe to get it out. the pre-cat sensor was a newer bosch sensor, it came out pretty easily. the code followed the bad sensor (which was the post-cat sensor). replaced it with a bosch unit (yes, i know - it has a one year warranty, though), no more codes. haven't noticed a huge change in engine operation, but it no longer falls on its face after upshifting, and seems to actually be able to hold speed and even accelerate up a hill without downshifting. it feels like it shifts a bit differently, too. but that could be my imagination.