"Pending" P030X codes, occasional engine misfire

[Rookie48]

Update on this issue:

I reset the throttle body adaptations yesterday, drove to home (~35 miles, 99% highway). No codes thrown, truck ran fine (no noticeable difference after throttle body adaptation reset).

Drove to work this AM, no codes, no issues.

I did have another train of thought on this --> the truck uses about 1 quart of oil per 1100-1500 miles. I had just topped off the crankcase (to full level on dipstick) before this all started to happen. In the first 200 miles since topping the oil off, it lost 1/2 quart (no drips, no leaks, out the exhaust I assume). Could the engine somehow, under high vacuum conditions, be sucking oil into the intake when the crankcase is at full level, and thus the issues of misfire could be caused by a short-term fouling of the plugs? That would not suggest why the codes are showing misfire on all cylinders however... and the truck did not smoke when running rough...

Confused...

[Rookie48]

Update on this:

Misfires returned after the adaptations reset...

Replaced fuel pump, fuel filter, and regulator. No change.
Replaced CCV valve. No change.
New plugs, coils. No change.
New O2 sensors. No change.
Removed OEtune flash (simply to rule it out). No change. (Actually misfires more now!).
New DISA. No change.
Replaced throttle body. No change.
Smoke tested three times. No leaks. No change.

WTF!! About ready to drive this truck into a pond/lake!!

Still only P0300 - P0306 codes begin thrown...

(Oil consumption has dissipated since CCV replacement. Was only 20K miles on the replaced CCV)