4.2 Spark Plug Fouling
I've got a 98 F150 SC and my check engine light has popped on twice in the past year. The first time was last November, so I took it to the dealership and they checked the codes...it was 2 fouled plugs. They replaced the plugs and cleaned the injectors and it ran fine for a long while (had 44k on it then).
I had my truck in the dealership paint shop so they could fix an issue with the clear coat on one of my fenders, and on the way home, I got a check engine light. Before this, the engine shuttered a little, was running a little rough, but when I gave it gas, it smoothed out. Right after it happened, I drove back to the dealership. Turns out it fouled another plug (has 55k) so they put on a new fuel filter, replaced the plug, decarbonized the intake and sent me on my merry way.
I love this truck, but I'd like to know what the heck is going on. Should I see about replacing the coil packs or put on something other than Motorcraft plugs or should I be looking for something else wrong under the engine bay?