Here's a triple play. Rebuilt Heads, plenty of compression. New Wires / New Plugs / New coil pack. Plenty of spark. Injectors fine. Inspected wiring from ECC to each injector / Fine , no shorts, etc. CEL Blinks and throws a PO 306. (Cyl. 6 Misfire) This occurs in gear. When this happens, A/C blows warm. In Neutral or park when 1st started. No CEL. A/C Fine. This only happens when cruising around. Ford has made 6 upgrades to the programming of the ECU since the original. The original is a F6DF-12A650-BE / This is an ML2-303 Flash calibration Unit. The current updated ECU is F6PZ-12A650-CVE. Realize this ECU's are the same, only the programming is upgraded. i just wonder if some of these issues were addressed in the new programming. By the way, The EGR is fine, there are no vacuum leaks etc. Plug 6 is not fowled and their is no coolant leaking into the cylinder. I wish it was that easy. I would appreciate hearing any ideas and similar experiences and possible solutions.