Nissan sentra 2006 manual give me error code P 0137

Question

generic circuit low voltage bank 1 sensor 2. I understand there are two sensors Which one is the one I need to replace? location? are we talking about the one downstream or closer to the muffler
Thanks
John

Answer 1

there are two sensors on this car one in front of the engine (bank 1 sensor 1) and the other one is under the car after the catalytic converter (bank 1 sensor 2 )