Thanks Shawn, for the fossil lesson. The GM engineers (Ha Ha) should have known this would become a problem and I think somewhere I read that, maybe it was Toyota or Nissan, actually added another fuel spray behind the valve to aide in cleaning. An Audi owner was complaining about an $800 valve cleaning service every 15,000 miles or so. So, why haven't we heard of a valve cleaning service recommendation needed at XXXX miles? Does GM not think this will be a problem? I might just be a little worried about the $50K truck in my driveway. Right now I have just under 7K miles but I plan on adding a Airraid tube so I will take a peek inside then. Thanks again.