Quick update for anyone in the future that cares to know this:
Only check engine light I got today was P0158 for a known faulty post-cat O2 sensor (no big deal but I want to fix that, too). Everything else looks to be on the up and up, and truck runs beautifully. Calculated about 17mpg on a 20 minute drive around town and into the country. NOT BAD.
Average fuel trims:
STFT B1- 1.02%
STFT B2- 0.44%
LTFT B1- 4.57%
LTFT B2- 3.03%
You must be registered for see images attach
This is a far cry from the thousands of misfires on cylinder 4 I was having before.
You must be registered for see images attach
I don't know what's normal or acceptable but this is much better and truck is running much smoother now. This was a ~30 minute drive.
Average ignition timing advance cylinder #1 was about 25°. Again, not sure if this is meaningful but the truck is running acceptably for me now.
The only other PID I have that may be meaningful is the Knock retard (degrees), but I never saw it change from 0. I am not sure if this is the same as CMP retard or not.
Anyways, if you're having a misfire at idle, P0300, P030x, definitely suspect the manifold gasket. As you can see in the pictures above, even some aftermarket parts were just plastic and silicone. They can sag in the middle and allow air into the intake. In my case, there was no coolant in the oil, or vice versa. Just extra air getting to a couple of cylinders, only one cylinder bad enough to throw the code.
The aftermarket Fel Pro gasket set with the metal gasket will hopefully hold out longer than the rest of the truck. While it was a PITA getting this job done, it's totally doable without any special tools. Make sure you study up, watch all the videos you can and follow the torque specifications on the valve covers and manifold (upper manifold if you do that, too). FYI the 1A auto video for replacing the lower manifold gaskets calls for complete removal of the power steering pump pulley and bracket, and alternator bracket. Neither was necessary, and I only had to remove 1 valve cover.
You must be registered for see images attach