So I got a CEL the other day. P0172. Called my dealer service guy. He said the code said it was running rich. Not a big deal. My door panel wasn't in yet so I waited until it came in to have them check the code and install the panel at the same time. Dropped the car off Friday morning. Quarter after 5 he calls me. Said they finally found the problem. Fuel rail was reading 120PSI! Fuel pressure regulator was stuck open. He didn't know what the tolerance for the rail was, but said it wasn't much over that. Looks like I'll be without my car for a while now. They stuck me in a new '06 Cobalt LS for the weekend. Supposed to turn it in today and get a rental. Hopefully it is better than a 4 door automatic...