Originally Posted by Bluegrass 7 (Post 14613553)

Either find OEM replacements or go to ROCK AUTO and select one of their well known brand names.
I would use a Scanner to look at the misfire monitors and see which ones need replacement if you don't want to go with a full set of OEMs.
The problem is the public likes the low cost but has no way of knowing history of them.
At least with OEM, FORD has used them from back in the early 90s on the first COP equipped motors on the production line to this day.
Like any part they do have limits on their life span but not like the unknowns or cheap imports or you would not have an issue.
I think from about 80k up +/-, the OEM coils can fail due to the very harsh climate they live in on any motor. After all they are a maintenance item same as tires, plugs, brakes or shocks.
They get heat cycled from the head temperature, heat from the radiator, heat from the exhaust manifolds and a closed engine compartment after the motor is shut down as the temp usually rises for a few minutes then begins to cool.
This breaks internal wire connections from expansion/contraction wire fatigue (sets a code) and can cause shorted turns that is the source of misfire in OD that 'does not' set a code..
Only here will you get this perspective and experience.
Good luck.

Originally Posted by Bluegrass 7 (Post 14614406)

...You have to get over this either not looking for the coil that is faulty by using a scanner or replace all the coils hoping one of the replacements is not faulty out of the box (it does happen now and then).
...
Good luck.

Originally Posted by FordTruckChuck (Post 14613556)

Thanks for the info, whateg01. I wonder if it would be even easier if the hood was removed.

Originally Posted by whateg01 (Post 14615631)

I don't think it would really matter. It's the cowl that really gets in the way. In my case, the hood was shading me from the sun beating down on that 100 degree, 98% humidity day with no breeze!

Originally Posted by FordTruckChuck (Post 14616928)

That sounds very unpleasant. I guess waiting for a cooler day was not an option.

Originally Posted by FordTruckChuck (Post 14616931)

Well I just ordered a set of 8 Motorcraft coils thru Amazon for $309.88 ($38.74ea)
& Motorcraft plugs thru ebay $2.99ea.
We'll see how it goes from here.

Originally Posted by Dr. Dirt (Post 14618653)

since yours is a 98 does it have separate coils for every cylinder. or is it just the 4.6 that has that?

Originally Posted by Bluegrass 7 (Post 20969859)

Even if this is an old thread there are things to offer.
1. If a coil is faulty and fails to output enough voyage under light throttle >>when the EGR valve is commanded to open, it is because the Air to Fuel Ratio becomes very Lean. this is norma but requires the coil voltage be above amin level to fire that charge.
If it does not, misfire is the result.
2. This can be verified by looking at the mode 6, test 53 record of misfire in the program.
This misfire record cannot set a code but keeps the history because the misfires come and go according to the driving condition.
3. The Oil stabilizer is a viscosity improver that would help improve Ring Seal more than affect the cause of misfire.
Just something for you in case the issue returns.
.
I use a 1 qt. of viscosity improver to 5w20 oil in my 25 year >newer engine< a 5L DOHC for an improved Ring Seal due to a factory quality control production issue along with another Additive to solve an Oil usage issue right from the assembly line.
.
Good luck.