Exactly what andrew just mentioned... -Check Xcal 3 for any error codes -Ring tuner and tell him what codes are, he can them maybe tell you some troubleshooting stuff if possible. -take car there and put back on dyno. goodluck mate hope it all works out, I had it happen to me once, very cold night I was booting it around, it overboosted and engine light come on!!, plugged my xcal 3 in, cleared all error codes and has never done it since. cheers