I'm sorry I wasn't clearer. Ford changed the head/spark plug/boot design effective October 2007 for the 2008 model year. The newer design had brown boots, mine were black. Nothing interchangeable. That newer design plug was much less prone to breaking. My understanding is if my plugs had been changed previously, I would most likely have stronger plugs, but that isn't known to me. I bought mine 7 years old with just over 100k miles. I have yet to change plugs and/or check and change COPs. Since my truck is running ok with only a slight bucking, I'm reluctant to open that can of worms.

 

You are slowly killing your cats by doing that. It doesnt take many misfires to kill the cats on this gen truck.

 

You aren't the first to tell me this. And I know that's an expensive fix. But it that's the case, why would Ford let this go on without a CEL?

 

Ford's threshold for setting a code is pretty high. A few misfires here and there wont set the code but does damage to the cat.

 

We never had CELs but yet we had to listen and feel what was going wrong . The CEL system is to help you without terrorizing you with every hiccup . Some mechy believe that cels tell you whats wrong. It doesn't --it takes a brain to figure all of it out only about 5 % of guys are good at diagnosis of hard problems .
True the government wants a trail to find bad emissions . If you live in those sates any CEL will fail you so there by you have to have a reasonable threshold .
Cats are expensive and too much fuel in them burns them up ,if you can feel the misfire you are getting damage . They warn you not to try and make it set a cel for this as the damage is cumulative and can be sudden .Cats are very expensive .
Doing a good plug job every 60k is your best bet .If this is your first plug job get lisle extraction tool on hand first .

 

Running plugs with excessively worn gaps stresses the COPs, even more so if the secondary fails to discharge.

 

I had your problem for four months before figuring out. I bought a Dorman Fuel Pump Driver Module one day because my truck wouldn’t start. Changed it out and it started right up. After that adjustment had happened the jerking started. I immediately was thinking coils. Whenever I had coil problems in the past it was at 45 mph and always was at that speed. I had scary bucking and jerking during braking. Then it would happen during acceleration. My truck would vibrate like it was going to explode. Go check and unplug your Fuel Pump Driver Module wiring harness. Check to see if there is a grey rubber gasket in there; if so, pull it out and reconnect it. Go for a test drive and let me know if it’s running different than before. I had that jerky, sputtering situation myself. I also threw a P1233 code that entire time frame.