Could be emissions yeah, before I replaced my MAF, my post cat O2 sensors were flagging error codes and had the same EML on the dash.
Replaced the MAF and reset the codes and nothing since. Simply resetting the codes brought the same ones back a few drives later.
You can use Carly for BMW app and a compatible obd cable. You will likely see other associated errors if it is also the same thing as mine, like "Minimum flow of secondary air" which is all related. Of the MAF is failing, then your O2 sensors won't be reading coreectly in turn.