have a PO140 code o2 cirrcuit no activity (bank1 sensor 2)

Question

where is this sensor located on my impala

Answer 1

P0140 - 02 sensor circuit no activity  signal Bank 1 Sensor 2

 Bank 1 is located where cylinder 1 is located and being a Sensor 2 make this a downstream sensor or the catalytic monitor sensor. When a 02 sensor degrade over time and use it goes biased voltage it is no longer able to switch in response to engine running condition