You Have To Get The Code Errased For Your Mil To Stay Out, Unless Of Course You Have Other Problems. You Could Have All Sorts Of Common Problem Codes, Such As Coolant Temp. Sensor(should Not Be Black), Maf Sensor To Name A Few. As For Your Fuel Smell , A Common Place For Leaks Is At The Fuel Pump. The Large Plastic Nut Might Not Be Tight, Especially If Some One Was In There. Lift The Seat And Remove Cover To Inspect.