Hello , I need help with my expo. It has a 5.4 , had the sesl come on said misfire /coil pack 3 . So I replaced . Reset codes and now it still misfires even more and no codes no sesl ! I ran an reader dio and its sayin that bank two is at 19.5% . bank one is normal. Not giving a reason why though. Odd smell from exhaust . Loss of power and misfires bad. Does anyone know of this problem ? I check injectors and coils and plugs , all seem to be fine. It runs descent first thing then within about 2mins its starts misfiring . I think it has something to do with o2 sensors maybe? Please help!!

 

I would have to say your misfire on #3 is due to a leaking fuel injector. It will cause both the misfire and the high fuel trim reading.