does your car cut off during anything other than idle, so you are coasting to a stop with the clutch depressed and it cuts off right, and at idle it will cut off right. if so it just sounds as if your aux air valve isn't controlling the curb idle. just set the ecu in self test mode and turn the idle screw to the left, maybe 2 or 300 rpms higher, but make sure to set the ecu or the ecu will not learn the new setting and you are back to square one again!! good-luck