I have a 2002 Firebird with the 3800. Occasionally I will get the "EGR stuck open" code P1404 after long distance cruising. It always goes away after a day or two. I have cleaned the EGR but no luck. I have read that a possible issue that is common on GM cars is EGR pattern failure, where the PCM does not give the EGR enough time to catch up, and therefore the PCM thinks something is wrong. In reality the EGR is fine, it's just not fast enough for the PCM's liking. The solution is to slow the PCM's check down just a bit. Any idea where this value is located? I will be getting HPT soon and this is one of several items I would like to fix. Thanks for any help.