its quit sensitive so i think there must be some sort of feed back signal from the throttle position sensor as the butterfly does not open much at all and with out something like the ark 4 the idle is all over the place and it revs quit high if you adjust screw on its own and once its out of adjustment you need some diagnostic kit to reset it to where it should be i known the ark 4 will do it but there hard to find so defiantly nice if could be done with a pscan diagnostic tool