Rough idle in drive

I have had this problem for sometime now with the truck idling rough in Park. All injectors have been replaced, and the Rail Sensor. Runs much better but every once in awhile it will come back. In speaking with my mechanic, he thinks that it could be one or more of the wiring harness to the injectors giving intermittent signals to the injectors. I have posted this problem on here before and I find it funny that I appear to be the only one who has had this problem!

 

run some lucas fuel treatment in it,double the recomended dose if it clears up its probaly the fuel control actuator on the pigh pressure pump

 

I would check and clean the ground for the ECM which is located on the drivers side near the battery and bolts to the edge of the fender. I would also check the ECM harness contacts (after unhooking both batts) for corrosion and water infiltration. This was a problem with some of our 03's.