About a year ago I had the tsb service done where they replaced the gas tank on my '05 GT. Since then I hadn't had any more problems until about 3 weeks ago. Out of no where I started getting this alarm on my dash that says replace gas cap. I got out a few times and checked and everything is fine with the cap and it is on correctly. However, every five minutes or so of driving I get the same warning. Anyone else have this problem?

 

Warning lamp indicates that either the cap is not sealed properly when tightened up-causes evaporative emission leak-thus turning on the cap lamp or it maight be a possible fault within the pressure/vapor valve in the cap. Be sure that the tether is not retricting full closure of the cap. If this doen't cure the problem-see your dealer.

 

I unscrewed it and then put it back on over a dozen times. I don't think it has anything to do with tether. I will definatly take it over to the dealer and have him take a look at it. Thanks!

 

I was getting the same message a few months ago and eventually the check engine light came on. I had no mods yet so I broght it right in to the dealer. It took a few hours but they found a faulty solenoid valve on a fuel vapor return line (in the engine compartment). They ordered and replaced the valve and no more messages....

 

I just called the dealer and they said to drive it another week and see if it resets itself. They said sometimes if those messages come up in error it takes a week or so to go though a full drive cycle for it to reset. If it is still happening after a week I will bring it in.

 

I got the gas gap icon on the dash and corresponding trouble codes and it turned out to be one of the vent hoses in front of the fuel tank. I'd run over a piece of truck tire and it knocked one of the them loose , there's no clamp holding them on ...