Been dealing with an intermittent downstream O2 Sensor issue on Bank 1 Sensor 2. Have seen both codes P0138 (low voltage) and most recently P0037 heater control circuit low, I'm tired of clearing the code and now that the weather is better I can finally replace it myself.

I've been frantically searching and I can't tell if I'm blind, but which side is Bank1/2? I've read conflicting things where someone said driver side is Bank 1 and another said Bank 2 is driver. Can anyone find a diagram of it, or know which is which?

Downstream driver side is a pain in the rear to replace since I read that the cable goes under the seat and then under the center console but from my quick check it looked like Downstream passenger had a short cable with the connection on the underside, so I'd much rather prefer that one

 

Bank 1 is the passenger's side.
Sensor 2 is downstream behind the cats.
The connection goes through the floor . Follow the grommet.
The connector is on the passenger floor in the FRONT LEFT corner.
If you peel back the corner of the carpet you will see the connector.

Bank 2 Sensor 2 is under the carpet directly below the drivers seat.
To access the connector, just slice the carpet . It's easier than trying to remove the carpet .
Besides it's under the seat. No one will ever see it.