here we go.. I took out the DISA valve actually I tried.. stripped one of the dam torx screws and .. wound up breaking the DISA valve because of that torx screw. And the bad news is the DISA valve looked good to me, the valve moved the piston ok, and if I plugged the hole to test vacuum and let the flap go, it moved to a 45 deg position which should be good or so I read. Ordered the DISA valve $286 original BMW OUCH.. should get it Monday.

Looked at the intake boot to the throttle body and Idle control valve can't see any leaks on the boots.. any suggestions would be appreciated. I have a spare car so I'm trying to DIY before I take it to the dealer.

Again symptom is, car would start no issue, idle would be slightly rough but not much and if I accelerate I have no power hesitation and it will stall. Codes pulled were lean codes in both banks, the other code p1115, however, that was only pulled once, normally I turn it off idles sometimes rough and if I accelerate then hesitation, and it will stall. So it only registered these codes once. I'm finding conflicting information on what a P1515 means.

Could it be the mass air flow sensor? If I pull the electrical connector from the MAF and turn on the car I don't see much difference except idle is maybe a little different but if I accelerate it will stall again. If I pull the MAF sensor cable while the car is running, then the car dies right away and MAF code is recorded on OBD II tool. So is the MAF ok?