Down to driver error...lol
..
The code could be related to the ecu seeing too much load, too little load or a uncontrolled deviation of load. First you need to know how the load is seen, Injested air mass is calculated from MAF value (mass/time) divided by RPM (1/time) to yield a mass. Standard mass is calculated by engine displacement (volume) divided by standard density (mass/volume). The correction which offsets the maths are air intake temps and and alltitude.
If your boost is about the same as it was when you left here, then your fault could be due to a naff sensor reading, or air being drawn in after the MAF. Check your tip connection to the turbo inlet, and clean the AIT sensors and see how it goes.
