O2 Sensor Location/ P0134/ Block 1 Sensor 2

I need to know where the location of O2 Block 1 Sensor 2 is. I know that it is either before or after the cat. (OBDII Code P0134).

All help is greatly appreciated.

Bank 1 is the left side (driver's side). Sensor 2 would be the second sensor from the engine.

Hope this helps.