I know the feeling. I seriously think mine is going to stall sometimes, but it never does. I've kind of started to not worry about it anymore. Sometimes while sitting
at idle it will give one big drop in rpm and go right back normal. Under very light throttle such as when stuck in bumper to bumper traffic is another common time for it
to act up. Completely random though. My idle appears to be about 650rpm based on the factory tach. Seems a little low to me. What kind of rpm does everyone else idle at ?
My car is completely stock. Also, the a/c compressor kicking in and out really sounds and feels extreme. Lights dim, etc.,. I think they even dim if the a/c kicks in at highway speed, but at least I don't feel it.
I like the recent discussion of dirty butterfly valve or something. Seems plausible.
Looking forward to hearing the results of cleaning that.