Slightly odd idle.

Anyone know what can cause a slighty off idle? It's adjusted correctly and idles right *most of the time*. But some times it drop below 500 and starts shakin. I know this a common problem, especially since I've got 151,000 on my 96 LX. But I know it's fixable, what sensors are causing this. The idle is also brought below 500 by turning on things. Now I realize that the idle is supposed to drop when you turn things, but this just seems to drop too much for how little I have on. Turn the radio on, 600, then turn the rear defrost on 550, lights, 500, wipers, *shake shake shake*. Or sometimes just simple coming to a stop at a light or something and it starts shakin. O2 sensor? MAF sensor? What do ya think?

Off-hand it doesn't sound like just an idle problem. I'd be inclined to think that your motor mounts are shot (just about certain if they've never been rplaced in 151,000 miles), and the shaking is making you think you have an idling problem.

Still that's not to say that soemthing else doesn't need fixing.