That's what I was thinking but the idle is controlled electronically in this car. Do you know of a way to mechanically bump it up a bit? I was playing with the throttle linkage but don't want to screw anything up. I know it can idle fine since it does in the morning when cold so why not when warm and what causes it to do this when it warms up? Also, I notice you live in So Cal and had a similar problem you were battling for a while. Did you ever get it solved in your vehicle? I'm thinking the computer is being fooled somehow to cause this low idle issue since it does this at a certain point. However, it can be a combination of things as well due to being old.