N55 rough idle/misfire at warm startup

[jkwhar]

Hey all, the symptoms are mildly rough idle/misfire when starting up from a warm engine for about 10 seconds. I can also feel it while cruising on a highway (this happens very rarely and when it does happen, its so mild that sometimes I cant tell if its the crappy NJ roads or the engine). I've been chasing this issue for a few weeks now.

2014 N55 with 120,xxx miles. To add, I don't remember having this issue before I had the car get its oil pan gasket and OFHG replaced. I've checked from what I can think/figure/find on youtube/tutorials the shop would've removed to make sure they didn't forget anything.

What I have done/checked:
-Checked ISTA and no faults/codes stored.
-Did a smoke test after the air filter to rule out leaks, nothing.
-ran misfire test plan on ISTA, nothing found.
-Did a misfire counter, and the count is random and jumps between cylinders (again, this only within the first 10 seconds)

Cyl1-1 count

Cyl3- 6 counts

And a minute or 2 later, I saw Cyl3- 1 count.

-I checked the rail pressure comparing it to the set point value and its very close to each other.
-Changed the spark plugs and air filter back in 11/2021

I'm leaning towards fuel or air issue since the misfire jumps between cylinders.

Probably forgetting 1 or 2 other things I've checked.

Any thoughts on what to check next? And, is there a misfire counter that doesn't reset on its own if it doesn't detect a misfire? It would be nice to get a misfire count on a long drive to see if the misfire happens in any other cylinders.

Thank in advance!