the engine will some times continue to rev and in fact increase to a point you have to turn it off, this problem is occasional but very frightening, I have had the bonnet up and witnessed the throttle cable go back to idle position yet the engine revs its head off on its own ??????????
engine revs up on its own on 2002 Hyundai Accent
If the throttle cable is returning to its rest position yet the RPM are high, if the car has an idle air control motor it must be either driven on by the computer in your car or the idle air control motor is sticking. Hyundai as a car manufacturer put a lot of free technical information and workshop manuals on line for Hyundai owners. Check out www.hmaservice.com lots of great information.
tps sensor needs to be replaced, have midas shop do the work and get the part from a local autostore to save money. by the way, go to midas.com and get a coupon to add with work needed to save money.