After removing the variable intake components in the plenum and sealing the hole i have noticed that around 35 mph my rpm's go from around 1750 and drop for a second to around 1500 then right back to 1750 ( when engine is warm).The check engine light no longer comes on and i have checked all around the intake for leaks with carb cleaner. I have removed the Idle air control valve and cleaned it as well as replced all the plugs, wires,filters etc.. It doesn't effect performance but is really irritating when it keeps doing it. Any suggestions on how to make it stop or what causes it? Also does anyone know of a Montero graveyard in Arizona? I bought a hinge there a couple years ago and have lost the web page. Thanks