I have a car that was draw through at one time. Someone changed it to blow through, I have been working at getting it better. No luck there and thinking about trying to go back to a draw through MAF location. This is a built engine and long tube headers making over 12 psi with a D1SC. My issues are MAF add counts fluctuating 50-100 at near no throttle, and runaway idle with near stock IAC values.