The biggest thing to do is find out why it is idling high. Biggest offender is massive vacuum leak usually. May also want to check Throttle Position Sensor, and maybe even Idle Air Controller.
Easiest thing is to throw it on the scanner, to ensure that you aren't throwing money at it. Also double check vacuum connections, routing, and make sure nothing is left unplugged. There was another instance where a loose egr tube was not helping with this same kind of situation, but no telling what could cause it.