I was having issues with a rough idle after start. Revs were sitting at 4-500, or the car would cut out. I'd blip the throttle, then they would pick up to 1200 or so before settling down. I came across this thread whilst troubleshooting, and it sounded like the AAC valve needed cleaning. However, I found a leak on the vacuum line between the throttle body and charcoal canister (tiny...only a few mm), Replacing that hose has fixed the problem. Sure it has been said in this thread before...but check for leaks, might save you unbolting the AAC!