I think I jumped the gun. Had the 1999 F150 5.4L out this past Saturday and we were all happily on our way when the engine appeared to of missed fired-or so it felt like. It did this a few times and went away until after 4 miles when we noticed a definate shuttering and slight loss of power-this is when the Check Engine light came on. We kept our fingers crossed and drove another 15 miles home with the engine running very rough. When I checked under the hood, I had a bunch of the mud dobbers nest-some of them right on top of the COP. I decided to clean the COPs and without even thinking, I disconnected the battery before proceeding-it was then I realized I should of had the codes checked at my local NAPA. When I hooked up the battery to see if the Check Engine light would come on when I started the truck-it didn't. I did notice that the oil gauge flickered to low and the oil light came on. It shot back up and the light went out-after doing this two more times, it stayed on for the few minutes I let the truck run, but the engine light never came on. Did I do a major goof by not having the codes read? I realize I'm asking a lot to look for advice with no codes, but I'm also wondering if the wasps nest on the COP damaged the ones they were on. Truck ran good for 15 miles before it all started with the sporadic misfire.....I'm good at taking advice and can follow directions to a tee.

 

You probably do have a bad COP. Just drive it until the light comes back on or if you have or can get a scanner that shows misfire [mode6] it will have the history of the bad cylinder. Did the miss come back after reconnecting the battery? I don't think the dirt dobbers [ thats what we call them in the South] had much to do with the problem.

 

How many miles on that 5four ?

 

Should of added that. I bought the truck with 72K on it and it now has 97K. Also, the engine continued to run a little rough after reconnecting the battery-though not as rough as it did when I was on the road.