In the install folder of the spectrum software, there should be a 'readme' file, that has the code.
Some 'old school' to consider on this truck.
The computer makes it run even down to 3 cylinders before you recognize it as bad, spitting or popping.
An o2 sensor out of range does not mean the o2 sensor is bad, it means the truck is either running lean, or the exhaust has too much unburned gas. I would start with a -complete-tune up.
if the light is off and does not come back after pulling the battery cable, the cause of the warning light being on is now fixed.