Had my 05 F350 6.0 for 2 years now. Put on a larger intake and exhaust and a Edge programmer about a year ago. I haven't had any issues with it until now. The truck idles rough intermittently. The programmer said it had a cooling fan circuit code and I replaced the cooling fan clutch today along with the serpentine belt and the thermostat. I have also replace both fuel filters. Everything i have change are motor craft brand parts. It ran fine until it got up to temperature then it almost died on me.
It almost acts as if a load is put on the engine then kicks back and runs normal. The RPM's fall a bit then kicks back up to normal. I have also replaced the batteries about 4 months ago. I'm running over to Ford to have them check the codes as I know the programmers don't always give all or the correct codes. Any ideas?