03 expedition 4.6 intermittent miss
 

I've searched forums and unfortunately i've not found a direction to go.. 160k on the odometer. New motorcraft plugs and recently new coils (accel) which i use in my truck and LOVE them. Anyhow, usually once per drive cycle I get a dead miss for maybe 20 seconds and then clears up and runs great. The only blame code i get is p0300. sometimes no codes. Im certain its only one cyl going down but i lose tremendous power when it happens. No noise from cats, and besides it runs too good typically to be a cat issue (i think). Never any lean codes or any other clues. Im beating my brains out here. This truck has done this since i bought it. 10000 miles. Any issues with valves sticking on these engines?

Could be the EGR valve sticking.

that's a thought... maybe I'll eventually get an egr code!

There should be misfire counts in mode 6 data. That will require a scanner to access a code reader cant do it. Also look for coolant around #5 these have a tendency to crack the intake under the aluminum coolant tube where the thermostat bolts. If you still have the factory coolant there may be white crusty deposits in the area. That is the factory stop-leak.