My father in law just called me and told me his 03 f150 175k with the 4.2 was running bad this am so he had the codes checked and it said 2,4,5 misfire and its also lean he went ahead and bought a new coil pack but does anyone k.ow what this problem can be he hasn't installed the coil yet, I just cleaned the throttle body and mass air censor a month ago and it has been running good until this morning, is it normal for the coil pack to go out like that, and the spark plugs are less than a year old

 

Help... Anyone, all these views and no opinions

 

I have read posts made that mentioned the coil failing quickly like that. I have an 03 V-6 and have been meaning to replace mine (168000) just as a preventative.

I will be sticking with a Motorcraft coil and not an aftermarket one.

 

He changed the coil today and still runs like crap

 

You may have TWO problems here. Lean codes usually point to a vacuum leak - most likely is the hose coming off the rear of the throttle body (primarily the elbow) going to the PCV valve on the valve cover. If that elbow's flat, or not perfectly round, chances are is there is a pinhole there. Is the idle sputtering, or high? Both are vacuum leak symptoms. While you're at it, check all hoses, since you're at higher mileage.