air mass plausibility: air mass to high, & mixture control: mixture too lean

[bluemagnet]

BMW x1 f48 (2016)
159k+ miles

I know this is not the x1 forum but that forum doesn’t have any knowledgeable technical members that could help me. I suspect there are more gearheads here who can possibly lead me the right direction.

The issue is that when the outside temp is less than 30 degrees Fahrenheit I will often get simultaneously two engine codes: air mass plausibility: air mass to high, & mixture control: mixture too lean. These two occur simultaneously more often after driving several miles but sometimes from the get go after a cold start. These two do appear when temp is above 30 but much less often. In addition there is always an idle hesitation from a cold start with temp below 30 as if the engine seems to want to die but as I let engine warm up the idle smooths out. The latter may be a separate issue. Not sure.
Before the codes appear while driving I get a very brief hesitation in the engine but then proceed to drive normally. The car remains operable and acceleration characteristic appears unchanged. Eventually the engine light and codes disappears on their own after several more miles of driving or the next day. I had done a smoke test that showed a loose intake connection that I corrected. I reverified proper intake seals twice with subsequent smoke test. However that did not fix the issue. The MAF, MAP and T MAP sensors are about a year old. No after market air intake or tune. Coil
packs and spark plugs are less than a year old. MPG on average remains 26-30. I always run 93 octane. I run 5w30
liquid moly oil that is changed by me every 3-4k miles. Air Intake filter is brand new.

I suspect that the codes maybe due to a problem with the high pressure fuel pump or fuel injectors. I think… Issue is definitely correlated with temps below 30. Thoughts?

[bluemagnet]

Anyone? 🙏