p0156:02p0161:02 which are these and where located,thanks

Question

2000 ford expedition 5.4l ,needs codes,p0156:2 and p0161:2 where are these located,thanks

Answer 1

P0156 -02 sensor heater malfunction (bank 2 sensor 2)

P0161 -02 sensor heater circuit malfunction (bank2 sensor 2)

This is the catalytic monitor sensor or the downstream 02 sensor for the catalytic.