Well, it looks like I spoke too soon. The car is acting up again only more frequently (every time we drive it) and more severely now the engine idles poorly. I thought I was saved when the check engine light illuminated, so I dropped the car off at the dealer. They read the code: Low Idle RPM. They cleaned the throttle body and asked us to drive the car to look for a change - there's no difference. The car is starting to feel a lot like a SAAB I had with a bad ignition cassette (I think Chevy calls it an ignition coil pack). What do you think?