Our 2000 RAV4, 4-door, automatic, 2W drive, has just over 100K miles on it. When warmed up and under load (like at a traffic light, in gear, A/C on) it idles roughly. My local mechanic reports that idle is completely under computer control, so it can't be moved up a notch. Since there are no error codes saved, there is nothing that can be done.
Is there something else to look at?