car cutting off could also be the fuel pump overheating and shutting off. Does it ever do it when you have a full tank of gas? Also the fuel relay can take a shit and act up when you hit bumps. (did it when you hit manhole). I got the hookup on exhaust pm me Ill hit you up with my number. I also have a chipped p28 with a nice WOT and partial throttle tune that we can plug in and see if that helps you. Im interested in boosting my car as well so if you give up we can just trade motors. Ill take you for a ride