bmw 750il 1998 po1270,po170,po173

I got this car like two weeks ago,runs good a lot power but check engine on ,no let me make emission,i reset couple times ,but is come back,any ideas what is located this problem,.
thanks guys.

These are mixture errors. P1270 is a MAF error, 170 is bank 1 lean, 173 is bank 2 lean. How many miles?

Thanks,has 185 k ,po173 is do it now we check maff by the computer,and driver side has 0.5 kg/H and left side has 7kg/H , wire or dme computer is bad ,i check the wires and are good,no sure how check the computer is post to be a minimun 6kg/H,no sure how check the computer,thanks again.