THIS MAY HELP , FORD (TSB 05-22-8) , DESCRIPTION: WDS COP KIT DIAGNOSTIC TIPS - COIL ON PLUG (COP) IGNITION SYSTEMS - ENGINE MISFIRE OR ROUGH RUNNING , ACTION: The misfiring cylinder must be identified through Self-Test misfire codes or through WDS Power Balance. Rule out base engine problems, rule out fuel problems, and then look at ignition problems (be sure to rule out coil primary circuit issues). Once the above steps have been completed, and the issue is in the secondary part of the ignition system, the oscilloscope procedure outlined in this TSB can isolate the difference between a coil or spark plug problem.
ANOTHER TSB
05-4-17 :INTERMITTENT ROUGH IDLE - NON-COMMANDED EGR FLOW
ISSUE: Some 1997-2005 5.4L 2V vehicles may exhibit an intermittent rough idle. This may be due to non-commanded EGR flow.
HOPE THIS HELPS