On my 2006 WRX the idle will drop when I turn off the headlights or other electrical things, turn the steering wheel, which I expect that, but it almost dies. Earlier tonight It just about stalled and caught itself. It idles up just fine when I turn on my headlights to acount for the draw. I also found after tapping the throttle when it comes back down to idle it doesn't always but sometimes sounds like it about to stall. Other than that it seems to idle smooth and run good. Something to be worried about??