Same issue bucks and check engine light replaced three coils and after a day it progressively got worse this time we received no codes, finally replaced all the coils and a vacuum line from the master cylinder and it seems everything has come back to the norm with a definite improvement in fuel mileage first road test was 200 miles towing another vehicle and no issues bottom line i suggest replacing all coils at the same time

 

My 2002 ford explorer 4.6,I've replaced the intake manifold, new cop's,brand new plugs.....my idle is rough, my oil pressure dummy gauge drops to zero at idle, goes back up when accelerate. I've replaced the pressure switch. If anyone else can please give me some input,it will be greatly appreciated.

 

This is the expedition forum.