2014 x1 35ix n55 lean mixture issue

[gysty]

Hi everyone, i recently bought a 2014 x1 with the N55 engine.
engine seems to have been replaced for a used one. it had codes for misfires on cyl 1 and 3 + lean mixture codes 2bc0 and 2774.
i smoked the entire engine and vacuum system and found a leak on valvecover, i did replace the valvecover, then i realized the injectors on cyls 1 and 3 were aftermarket, so i got new factory injectors eu4 which are the ones that calls for that car, also replaced the spark plugs, and oil filter housing gaskets since they were leaking. all codes ar gone except for the 2bc0 and the 2774, they clear when i delete the codes but as soon the car starts it idles rough and then smooths out, same codes comes back. maf readings are at start 24.4 and when it smooths out goes down to 11 or 10. what am i missing here? valvetronic motor can cause air fuel issues and o2 sensors, but o2 sensors i tested the issue by disconnecting the o2 sensors and idle does the same, same codes + of course o2 sensors, the car drives good all the values are ok. smooth running values are ok fuel trims are ok the problem is only when starting the vehicle either cold or hot, it always runs rough and the smooths out. another code that popped out is 28a0 throttle valve opening angle absolute pressure intake pipe comparison too high.
what am i missing here.

[gysty]

anyone have any similar issue before?

[illiniCS]

Could it be coil packs going bad? You mentioned you changed the spark plugs. Or possibly carbon buildup on the intake valves? I recently bought a 2013 35i and mine looked pretty dirty so I walnut blasted to clear them. Though I wasn’t having issues like you describe so could be something else too.

[gysty]

Thanks for the reply and the guess, coil packs will set a different set of codes however yes i swap them from my other bmw with same results.
im waiting for the weekend to swap the throttle body and check.
my other guess is that since it is unmetered air codes, maybe the valvetronic is acting erratic changing valve opening and causing the unmetered air. and last wiring, i checked already and it checked out ok but who knows. something shady is going on in there.