you may have one or more issues
first off your maf readings are way too low for given boost, this could be map sensor reading high.
try logging atmospheric pressure and actual boost pressure, start the car log for a few seconds then ignition off for a few seconds and back on without cranking or starting for a few seconds then crank and start for a few seconds.
this should compare the map sensor to real atmospheric at ambient condition and then when running at idle, it should be fairly close to atmospheric reading and shouldn't alter that much when running at idle maybe 50mbar or less ? if you let it log for too long before cranking it may revert to a false reading(mine stays at 1013mbar after a certain time(when just ign on not running))
or it could be maf sensor reading too low .
this could be a few things , maf gone , restricted inlet coked in carbon , swirl flaps stuck shut, inlet antishudder flap stuck closed partially closed, split turbo inlet hose maf to turbo or breather pipes that join after maf.
all could give a low air flow yet high boost pressure occur.
with egr physically blanked I think the 2.4 should be somewhere around 485mg/I of maf at around 1000mbar atmospheric , so 960mg/i @2000mbar 1150mg/I @2400mbar etc
straight away maf low at idle looks suspicious, as its less likely to be splits in hose as theres not really much vacuum to bypass the maf.
you could do with a donar car to swap map and maf sensors to confirm after checking visuals mentioned above.
you could unplug the maf and test drive, car should revert to internal maf values derived from boost values.
also you could add total fuel to a log, low maf values will restrict fuel qty
actual boost and vnt % appears to suggest its not a choked intake or map sensor over reading as I would expect it to be dropping vnt more on max boost areas.
the strange thing to me is where the boost pressure drops into 800mbar ? unless its function of antishudder flap working with egr to create vaccum to draw egr , your egr is blocked but maybe antishudder still partially closes where egr would have been active.
Good point with MAP/atmospheric pressure :-) See attachment, they looks fine in my eyes.
I remembered i had a new MAP in stock, so drop that in..No change.
I did also open to the shutter today. It was wide open...Should that be closed when car is stopped, or does it open after stopping & thats what you hear a few secs after the engine stops?
I think shes perhaps like 3-5 MPG down from when it happend? she does approx 37 MPG at 65 MPH on straight out level roads..
At 1000 RP/m theres a judder, otherwise engine is very smooth, perhaps a bit rough from overfueling (Black smoke when max torque & <3K revs)
I have looked through the pipes in the inlet from MAF to manifold (Except IC), but no obvious leakage.
You might just have explained to me why the 800mBar thing is happening, as this have really mystified me..Especially cause it only does it when warm
Tomorrow ill try to get hold of a tirevalve & then put the entire inlet under small pressure & then do a thorough leak-test.
Thank you so much for your time & inputs for now :-)