What is your temp at? There are some calibration issues with them not warming up quick enough throwing that code. Mine does it occasionally, and now I have determined that my thermostat is stuck open since it never gets above 180 unless I'm towing.
I use Peak's Final Charge. I ditched the Ford Gold with my last flush. Very happy with it thus far. You can look up threads on here with lots of discussion about Ford Gold or making to leap to use other ELCs. Peak claims the Final Charge coolant is formulated for all heavy duty engines and created from over 10 Billion miles of testing. Look it up under commercial grade coolants.what coolant is the best to run, I read that the 6. 0l run specail fluid not sure on the 6. 45min tho