I thought that bank 1 was the bank w/ cylinder 1 which is on the passenger side on our cars :dunno: Either way usually when it says "Sensor" and "bank" all in one code it means the 02. The sensor number coresponds with the sensor on the manifold (Sensor one) and the one on your Midpipe (Sensor two.) If its Sensor one the car could be running lean or rich depending on how the bad sensor is reacting, do to the fact that the first O2s measures A/F. Could be talking out of my ass but this what i tell my customers considering a Manager at an Autozone :
get yourself some MIL eliminators if you want the code to go away. Your 02 sensor is probally not bad, you are running and o/r midpipe meaning no cats meaning o2 sensors are picking up different readings than stock if you had cats. Changing any sensors will not stop your check engine light from coming on. this is what the MIL's are for.