With the car idling warm and such (when you start to see the high idle), pinch the bypass hose that runs before your throttle plate to the back of your intake manifold. If the idle stumbles and the car tries to shut off, then it's not the AICV. If the car doesn't change much at all, check for vacuum leaks.
Some hoses and connections seem fine on first start, but then after being under the hood while running they start to leak some. Mine does the same thing and I know it's because I have tiny vacuum leaks in some locations that are only affected when warm.