Yes, check throttle cable and Cruise control cable if so equipped.
Open and close them manually and see if they stick and make sure throttle return spring is not broken, this spring needs to be tight to close throttle and block air flow.
Other thing to check is the IAC(idle air control) valve.
It is located on the upper intake near the throttle.
This is a valve the computer uses to set the idle level, computer opens it a bit to increase idle and then closes it to decrease idle.
Not sure it could raise it to 5,000 even if opened all the way