Bandit, which type of MR2 do you have?
If it is the turbo, which cat are you referring to?
carcatz, you do not have to reset the ECU is you overboost (hit fuel cut).
You just need to restart the car in order to boost properly again.
Fuel cut kicks in at 12 psi. If you want to run 12 psi or more boost, you need to buy an HKS FCD (fue lcut defencer) OR disabel fuel cut.