2007 4.3L misfire when idling but not so much when driving

[07FORDEXPEDITION]

I have a 2007 Ford Expedition with 5.4L 3v. I have had P0340 and P0344 codes for some time. At that time it would run rough at idle but not when driving. A little while back it started misfiring on 03 primarily when idling . The spark plug was swapped , coil checked and it still does it, however, it does it at idling but when I drive it and monitor the misfires it doesnt do it so much around 40 and above. Any ideas?

 

[Thunderbirdsport]

I'd put new plugs in and take 'er for a rip. Beware though, unless they've been changed with the newer one piece style, yours could well be the two piece design that are prone to breaking off. If so, you'll want/need the Lisle tool to extract 'em.

You know....Ford...."the way forward"...smfh LOL. (and my blood runs Ford blue, too.....)

 

[Motorcity muscle]

Seems odd that it is a reacurring misfire in three, was the issue before the same as far as only at idle.