Could be a defective oxygen sensor, exhaust leaks upstream of the oxygen sensor, thermostat opening at two Low of temperature, or even late ignition...
Missouri, southern Ozarks here. Welcome. Trouble codes and any other drive symptoms would allow us to help you. Make sure your O2 is working properly...
You never mentioned an inverter/charger but by chance are you using one ? I was getting horrible corrupt data, more packets lost then received. Then...