Need help with errors

[Mechcanico Lee]

Can you hear any hissing when under boost e.g inter cooler or associated pipe work leaking boost
Look at both air flow meter signals and compare on the road to see the difference ,if one is way off to the other .
Negative deviation is a fancy term for boost being low for given load factors .
Try to look at both turbo actuators get someone to turn ignition on and off and see if actuators do a 'full sweep' with a smooth action ,or see in the vcds actuations menu to see if you can drive them .
Air mass meters rarely give codes because the signals have to go through such varying load factors ,the air mass signals are not interrogated by ecm control , it's the consequential effects of it that the ecm picks up on such as wastegate control
If the turbo wastegate controllers are electronic they should flag codes because they have feedback to ecm e.g if the variable vanes where sticking
The 3l v6 jags flag 'p134b turbo control fault 'when it sees sticking vanes or high load feedback on the motor controller .
A few things there to go at