Bank 1 is the driver side.
That is the O2 sensor behind the catalytic converter.
02 sensor circuit slow response bank (bank 1 sensor 1)
Bank one sensor one on a 2006 Ram is before the catalytic converter on the driver side.
That is the sensor in the catalytic converter.
Trouble code P0161 means:O2 sensor heater circuit malfunction (Bank 2 Sensor 2)
Not knowing what engine you have in that 02 Dodge, the bank of cylinders on a V6 or V8 that contains the #1 cylinder is bank 1. Sensor 1 would be the first sensor threaded into the exhaust system after that bank.
Trouble code P0546 means:Exhaust gas temperature sensor circuit high (bank 1)
It actually screws into the middle of the cat.
Bank 1 would be the bank of cylinders that contain cylinder number 1. Bank 1 on the 3.9 would be the bank of cylinders located on the drivers side of the engine. Bank 1 sensor 2 would be the O2 sensor located after the catalytic converter.
Bank two is the passenger side. Sensor 2 is the one that is down stream(after)of the catalytic converter.
2/1 is the 2nd bank upper sensor. The 2nd bank is the side with the number 2 cylinder, in the case of the 4.7, the right side. The sensor you are looking for is the right side (passenger side) upper (before the catalytic converter) o2 sensor.