Hey guys i have a 03 supercrew with the 5.4 in it. 84,000 miles. Engine light came on and i hooked my code scanner up to it and it came up a P0125(CISD LOOP FUEL INSUFFIENT COOLANT TEMP) sounds greek to me any ideas on what it could be the truck is running fine just hate to see the light on the dash. THANKS

 

I would get a new thermostat
P0125 Insufficient Coolant Temperature For Closed Loop Fuel Control

 

Yep, replace the thermostat. Yours is getting lazy and is taking too long to open.

Steve