I was just driving it about three hours ago then the check engine light flipped on at a light still drove all the way home shut it off then I waited I started it again fine I thought but check engine light was still on then I go inside three hours pass get in to start and it won't start but it cranks. So my question is. Would this be the mass air flow sensor or the crankshaft sensor or maybe even something else and help is appreciated. Thanks for reading!! Oh yea doing it myself so maybe an idea of level of difficulty