iv got a s2 rst, when i dive it hard the boost peaks bout 17psi and holds bout 10psi wiv my right foot planted it suddenly stops,rev couter goes mad then it back fire's then goes again. seams to only do this flat out in 3rd and in forth.the ecu has bn chiped and got a -31 actuator.

 

symptoms of boost cut
you sure its chipped?
or chip hasnt got a boost limter set
also a 17psi peak is a bit high for holdin only 10psi of boost

 

That clearly isn't chipped if its cutting out at 10psi in the higher gears.

Turn the boost down and take it for a rolling road set up, or it will go bang!