well i had no no problems before i installed my new head gasket head studs and new lightning 1 100 hp injectors! when i fired it up and took it for a drivei was less than happy. it seemed to ........hmmm should i say shudder for lack of a better word at 45-55 mph appx. seemed really obnoxious till i uninstalled the superchip.problem got a bit better. i tried the apps reset also seemed to help a bit.i still now have a vibration so to speak (the kind if you have a manual trans and you are in 5th gear and doing like 15-20 mph you get that bucking feeling) thats what i got.but only when i give it light pedal pressure. as soon as the trans/tc hits lock up there it is.it goes away if i push the overdrive off button. to me it seems like now maby with the new hp maby the VB needs to be adj. ???mayby the low end shift points screw? not too sure any ideas would be helpful?