02 sensors are hard to guess the age of, I've only owned the truck for a fraction of its life and they certainly weren't replaced under my watch yet.
However the data from the OBD-II scanner doesn't lead me to believe they are faulty. they both show similar warm up times, 02 readings, voltages, etc that implies to me that they are both functioning normally.
The only explanation I could think of that would pertain to the 02 sensors being at fault is if my exhaust leak could be allowing ambient atmosphere into the exhaust pipes and allowing them to perceive an excess of oxygen in the exhaust.
However I intend to both attempt to rectify the exhaust leak/02 sensor probable cause, as well as investigate my intake plenum