So, I think I have a solution that will work. Although the G3X does not have an input dedicated to an Oxygen sensor, there is still a way. I can plug the analog output from the sensor to the input for fuel tank 3. Then configure the fuel tank to display empty at 10 gallons and full at 20. Then configure my arcs to display green from say 10-13.5, yellow 13.5-15, and red 15-20. Although not perfect, it beats having an additional sensor display on my panel!
Garmin, please give us the ability to select O2 sensor on the next software update!!!