oxygen sensors

I am wanting to find out on the sensors which bank is which . code reads os bank 1 sensor #2 . and before i go and replace one by one . i justed wanted to know .v-6 4.3L

I am wanting to find out on the sensors which bank is which . code reads os bank 1 sensor #2 . and before i go and replace one by one . i justed wanted to know .

Bank 1 will be the side of the engine with #1 cylinder, so on your truck it will be the drivers side.
Sensor 2 will be the sensor behind the converter

Bank one is the side that #1 cyl is on, sensor 2 is the second sensor in line on the pipe from that bank. Didn't tell us what year or engine ( common issue on these forums), so that's as much as I can tell you.

Also a 02 sensor code does not say replace the sensor.
It says check it out first.
Like maxwedge said no year no engine and no code no does not get you much help.
MT