I have a 1997 Honda Passport 3.2 engine that idles high around 1500 ot 2000 rpm while driving and the truck has been driven for 1/2 hour. If I turn it off and let it sit for about 5 minutes, it disappears until I drive it for a while again... any ideas?

Thanks

Ninpo23

Sounds like a leak in one of your vacuum lines. There's only about 150 miles of them under the hood, but you might want to check! Try spraying some WD40 here and there in the engine compartment while the truck is idling, if it changes idling speed in a certain area, check there for a bad hose.

Consider replacing the Ignition Control Module:

Zip Code Entry at PartsAmerica.com

Had a 97 Ford Expedition that had very high idle at times when driving or stopped. I replaced the IAC (Idle Air Control Valve) for $55 bucks and that did the job.
Hope this helps.