idling issues - mixed up error codes

[mik15]

so for the last few weeks i have been experiencing some idling issues, waiting at the traffic light it has moments when the engine almost dies, the rpm goes so low that it almost stalls if in N, if i keep it in D, due to the load i guess, it is better but still lower RPM than cca 760 which is the usual one...

then taking off takes a bit of struggle, feels like it's chocking, once i get rolling it starts running as it should.

All of the above are intermittent, some days can be all good, then the next day it goes back to rough idling..

Errors so far were only the ones Fuel Trim related, on both banks, which were either showing system too lean or system too rich, both ADD and MULT, and all intermittent, except the one on Bank 1 which seemed to be permanent and it was ADD, if i remember well.

Now, another thing i noticed, on one of the scans, the MAF on bank 1 was reading 10mg/s compared to 5mg/s on bank 2, at idling.

This makes me think there is something wrong with that MAF, but today after a similar experience with almost stalling and later all being good, did again a scan and both MAF's were reading 3.6mg/s and no errors were stored.

So, what is this related to? Could only be the MAFs? i have already ordered a set of gaskets....

Could be the chocked fuel filter? or a dying external fuel pump?