Bank 1 is the driver side.
On a 2006 Dodge Dakota bank 1 sensor 1 is driver side above the catalytic converter.
That is the O2 sensor behind the catalytic converter.
02 sensor circuit slow response bank (bank 1 sensor 1)
Bank 1 sensor 2 would be the sensor after the behind the catalytic converter.
Trouble code P0161 means:O2 sensor heater circuit malfunction (Bank 2 Sensor 2)
BAnk one sensor one is above the cat on the back exhaust manifold. Sensor two is below the cat.
It is the sensor in the outlet of the catalytic converter.
Sensor two is closer to the muffler.
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)
PO136 on a 2000 to 2003 Dodge Dakota (It may be true for other year Dakotas) means "Downstream oxygen sensor circuit problem (left cylinder bank)". This is the oxygen sensor that is located just past the catalytic converter on the driver's side and measures the oxygen level after the exhaust has passed through the catalytic converter. I
It actually screws into the middle of the cat.