Alright, so still having the issue although it has morphed into more of a bad missfire? So before when it started, the engine would just die out when I hit the accelerator but now it's more of a chugging/missing/shuddering feeling for a bit and then it tries to die out. So the symptoms are evolving with the repairs... I did get another P0174 code on this test drive too. I haven't changed plugs yet, I'm kind of leaning toward that as a next step. Still everything on the scanner was looking pretty good and the computer isn't registering a misfire but it definitely feels like it's missing.

 

have you ran the compression test yet? you could have a weak cylinder. Definitely pull the plugs and show us a pic of them by cylinder if you can. don't use champions or Autolite plugs even tho its a 4.2. JMO of course

 

Here's the first two I pulled, then I had to take care of other stuff. They're motorcraft platinum, and I could barely make out the writing so I'm thinking they're pretty old and looking pretty worn out

 

that looks like a hell of a large gap, but with pictures who can be accurate. They do look like they were firing, but the gap has me at a loss for how wide it is.

 

The top one is definitely deteriorating. The bottom looks OK to me, but like AK said - it is tough to tell from the pics. Do you have a gapper you can check the gap with? Curious what that top one is at.

 

I agree, the gap is excessive. That can cause a lean condition because the plug isn't getting a good burn and can lead to hesitation and stalling. This is one of those situations where I lose it with PCM mapping. There's an O2 sensor identifying too much O2 and a knock sensor that should be identifying bad ignition from not enough fuel for air. The plug doesn't show any signs of pre-ignition or bad timing. But, this type of conflict should lead to a CEL which you don't have. ?????

EDIT: sorry meant O2 instead of fuel.

 

Is the 4.2 a waste spark system? Is that a single platinum? Looking at these pics, they are probably single plat, and that top plug is on a reverse polarity side. Double plat will be a better plug for you.

 

White, this one goes over my head, can you explain this please?

 

When Ford used the coil packs (Not COP's) on motors, two cylinders share one coil. This is called a DIS or waste spark system. One side is reverse polarity as a result. They both fire at the same time... one on the compression stroke, and one on the exhaust.

 

https://www.f150forum.com/f6/how-che...-packs-244392/
Yes White, according to this, they are.