5.7 hemi rough idle and low backfire out exhaust any ideas

So if you are replacing bank 1 sensor 2? you don't have a sensor 2 if your not running cats.
You only have 2 O2's correct, 1 on each side? you should have a 4 wire connector on each.
1 power for heater, 1 ground for heater, 1 sensor in, 1 sensor out. You could have a vacuum leak and the O2's see the extra oxygen and ritchen up the mixture to full rich.