Re: Unusual boosting problem
 

I see you have tried all sort of things already. Did you try a different tuning program? There might be a glitch in the current program that is activating boost-cut.

Re: Unusual boosting problem
 

I have seen this happen before...but usually the boost cut feels very violent, like a rev limiter. He would probably notice that.

Re: Unusual boosting problem
 

Did he ever drop the exhaust. Its usually the simpliest thing if the motor is healthy etc

Re: Unusual boosting problem
 

Do u have any filter ? ::)