Evaporative Emission Control System Leak Detected(Gross Leak). You either have a crack in your gas cap, or a leak in your gas cap seal. I suggest buying a new gas cap just to be safe.
Evaporative System Malfunction, Gross Leak. you need to seek professional help to correct this issue everytime a change is made to correct the problem you will need the computer code
This indicates a leak in the Evaporative Control System caused by a faulty or leaking gas cap resulting in low gas mileage because the fuel is evaporating.