Boost cut is just that, the ecu will NOT allow prolonged overboost over aprox 14 psi, id suggest the problem is not related to the ecu chip.

Have you carried out a Stage zero tune? this is paramount when buying one of these cars they are all getting old and most have been abused, and before any tuning is carried it is highly advisable it then allows easier trouble shooting, and possible even stops silly issues in the 1st place.