Ford Repair: warning light, hello bill, ford ranger

Question
My 2004 Ford ranger has the gas cap light on.  This came on for no apparent reason as I was driving.  I checked the cap it's on tight.  Any suggestions

Answer
Hello Bill, The light is on because there is a vapor leak from the gas tank. The leak can be from the cap, cannister(which is a filter), check valve or a line fitting. I know a dealer can perform a diagnostic which will pinpoint the cause by using a computer and a tool that puts the system under low pressure and pumps a harmless smoke into the syatem so they can look for a leak. You can try replacing the cap 1st but if you do I do recommend to get a cap from Ford. I have seen issues with aftermarket caps and not fixed anything. Hope this helps Thanks Tony