the response the AFM gives the ECU is proportionate to the boost, its the ecu which compars the singal form the AFM to its map table and will decide that there is too much air coming in so shut down, my evo 6 did this one a free flow pipe, decat and air filter were fitted, the best solution at the time was to fit the ralliart sport ecu, this was simply a plug and play swap of the ecu which allowed boost levels of 1.5 bar safely, the airflow itself though is not just dependant on boost produced, the density and temperature of the air are also calculated and taken into consideratiopn, so for axample my car would boost cut at 1.1 on one day and then only 0.95 the next,

other option is to bin off the AFM and fit a map sensor with a ecu mapped to it

do NOT use fuel cut defenceer as all it does is modify the singal form the afm and kid the ecu that it is actually gettin gless air than it is - risk of running lean badly and conditions for maximim smoke