Our 2010 Expedition with the 5.4L just hit 148k miles and was running fine. I had ford do the tune up with new plugs and a coolant flush. Now it has a intermittent miss. My wife describes it as like it gagging while trying to start or someone is shaking the vehicle. Took it back to ford and they could not recreate the miss or find any codes. Any idea? Possibly a coil failing? Is it coincidence that it’s now running rough or did they screw something up?