Yeah Ive got a surging issue also. Over the past 6 months I have changed valve springs, Coils, spark plugs (twice), fuel filter, got different fuel from several servo's, been back to a reputable(forum sponsor) tuner 3 times and they claim to have solved it opn the dyno but havent. Only thing that did fix it for a short time was getting new coils. Fixed it for a week, but then again it could have been all in my head. Im thinking its my gearbox but only in 2nd gear(ofcourse I have no basis on that just that it happens only in 2nd gear from lower rpm WOT. After tax time Im going for second round of power mods and a new tuner, hopefully may solve the issue Good luck hunting it down and let us know if you figure it out