the past fewmonths i've noticed the idle is a bit rough to the point it feels like it might die but never does . Today It got worse and now there is alot of vibration (cabin/engine) especially between 8-1200 rpm when I tap on the gas its worse and Its obvious when I'm driving at slow speeds, within the same day the engine light came on.
I checked to make sure the gas cap is on tight, I put in a new air filter and still the engine light stays on solid, expedition has 98k.
Heard it could be an o2 sensor? or bad coils?? let me know, thanks.

 

I'd start with the coils. Check the converter - could be an early failure. Also checking the trans fluid wouldn't hurt.On occasionyou'll get vibration from simple things like a wheel out of balance which can make excessive vibration and set other things into having their own trouble. Although an unbalanced wheel, etc would be more noticable at certain speeds than others. A speed sensor or other sensor could make trouble too. In short the newer the vehicle the more the trouble no matter what company makes it but I can say Ford seems to be often the easier ones to want to have to deal with overall.

 

I'll vote for one of the coils failing, probably a misfire code.

 

yeah,I took it to rhodes automotive here in denver and they said it was a coil and i guess a heater hose under passenger side of engine near the clamp was driping coolant down into the coil. Got that fixed and along with a tune-up plugs/wires, its driving great now.

 

How much did the cils cost you????

 

The dealer just got 90 bucks out of my brother in law for a failed one on a 5.4l.