Scotty - We've got a 2002 Escape with 219K miles and a 2006 Odyssey with 255K.  We've had them both since they were new, and both are in remarkably good shape.  We've never gotten a Check Fuel Cap light on either vehicle with the exception of one time a few years ago when I drove the Escape home after getting gas with the cap dangling.  I cleared the code, that was a non issue.  Two weeks ago we drove both vehicles to rural South Carolina, spent the weekend there, then left to drive home 30 minutes apart.  In the morning, the Check Fuel Cap light was on in both vehicles.  This seems statistically unlikely that this would happen, essentially for the first time on both vehicles, on the same day.  I have no idea if this is related or not, but as we left SC, we both stopped for gas, at different gas stations, but they were the same brand and owned by the same family, so I'm guessing their source of fuel is the same.  That Monday morning I called the dept of Agriculture, intending just to ask if they had any idea if contaminated fuel could cause the check fuel cap light, and if others had the same issue, I wanted them to have a few more data points.  They offered to test samples from both stations.  They sent me the results the next day and everything was nicely within the ranges from both samples.  I cleared the codes on both vehicles, and no issues since.  Any ideas?  Do you think this was just pure coincidence?