Since all of the sensors share a power circuit and you only are getting one code I believe the power circuit is most likely ok. Either there is a problem with the sensor itself or the ground circuit.
The proper way to test this circuit is to find the sensor. It is on the passenger's side after the catalytic converter. Closest to the rear of the truck. There are two sensors on each side. Disconnect the connector and use a volt meter to check for battery voltage on the red wire. If that is ok, then check the resistance of the white/black wire between the sensor connector and the engine computer. If that is ok, you will need a new sensor.
95% of the time this code is caused by a bad sensor.
Hope this helps, if you have any further questions do not hesitate to ask.
How can I tell what o2 sensor is the bad one ?? There are 4, am I right ? I changed one maybe 4 or 5 years ago. What does bank 1 and bank 2 mean ?