100K+ 2007 mini cooper S unmetered air leak

first post I got a 2007 mini cooper S in January with 114,000 miles. had a miss in #4 cylinder. did a head job found one intake valve broken. complete work over on head. got it all back together... have a code for after thottle air leak... using an Autel scanner.
So far.. replaced the PCV hose from valve cover to intake - replace the intake - replaced the valve cover ( PCV orange rubber disk gasket damaged)
pulled fuel rail (again) just to make sure no sealing rings were broken or missing. checked all fittings and air hose connections.
in the rebuild NEW vanos / camshaft sensor / oil sending unit / thermostat housing / rebult oil filer base / installed new Turbo / turbo oil return line / pre CAT O2 sensor / timing chain and related guide's / used but new vacuum pump / plugs / coils and a few missing screws bolts and nails.
reactions: car starts great runs 3 to 4 minutes then idle start going up and down (by tack - 100-200 revs) if i raise tack to 1500-2000 the car will run 4-5 minutes ish. then starts slowing down. code reader live data shows lean condition and rate up and down 200-300 revs. keeping it running and clear codes it all goes back to normal and runs again for 3-4 minutes . then just up and dies.. actual code states unmetered air leak - after throttle... WHAT am i missing here.
I have not changed vapor purge valve but have checked all hoses in engine bay and the all all good. vacuum pump good no leaks there as it can sit for 3 days and when i pull a line off its still holding vacuum you can hear the hiss sound. this is not my first mini job i own 5 of them now 2007-2008-2009-2010-2011 Any information will REALLY be helpful. thanks G