Auxillary Fuel Tank

Thanks all for the comments. We believe the problem has been resolved. The capacity in the tank, more empty than full, has a lot of "AIR" space, so when the fuel gets a bit lower it is more difficult of the vacumm to be maintained. then again, a re-seal of the gas caps seems to work as well. The check engine light has gone off on its own and all seems to be working well. The dealer, and my service adviser will work with me on this next time in the shop. Again, Thanks for all the comments. Good Luck & Be Safe ! ! !