2011 Ford F250 6.2L 5 star tune,373 rear,85000miles new plugs wires at 75,000miles. Just started this a few weeks ago runs great after warm or about 6-7 minutes. tried bottle of Techron & dry gas. any ideas or stuff i could swap out to try? No error codes either.

 

Mike,
Did the plugs have screw on type connectors on top (where the plug wire attaches)?
Were the seats for each spark plug hole clean? (It is an electrical connection so CLEAN is important)
Were the wires routed in their guides/brackets correctly. (Thus separating them and assisting in eliminating cross fire.
Eric

 

The 6.2L has 16 plugs (I didn't know that ) I'm pretty handy but being that it's an aluminum head and some plugs are hard to get to I bit the bullet and let the Ford dealer do it they also changed the wires at that time.(I will check the guides today thanks) There was no issue before the plugs I just wanted them changed cause I bought the truck with 65,000 miles & figured it might be due. It has always run fine cold or warm now just skips when cold (about 6 minutes). Yesterday I did a reset of sort removed battery terminal then shorted them out for a minute then started truck and let idle for 10 minutes then drove around for a while. Today I'm going to start it and drive down town immediately and see how she runs.