Thought I will share this with folks who have the same problem. I have a 00 Boxster and the engine had idle problem a few months ago. After doing some research, I cleaned the MAF (Easy DIY) and it fixed the problem. But the problem comes back periodically. Last weekend, I removed ICV (Idle Control Valve) and cleaned both the throttle body and ICV. BTW, it was very very dirty. Now the engine runs like a charm. Those of you who have the same problem might want to give it a shot. This could have cost you serious $$$ if you take it to the dealer or a mechanic.