I have a 4.0 six, the engine light is on, if I was to put seaform in the tank the light will go off, when refilling gas the light will come back on in time, sometimes, when I first start the jeep the engine will make noise and take off, for about the first mile the light will flash and the engine will cutout. After about a mile, the engine light will stop flashing and go back to solid light on, the engine will stop cutting out and runs ok. I did once had a code check and code reader only said misfire.