2007 Chevy Trailblazer Engine Light stays on

An engine light is designed to come on when the computer senses an electrical engine problem, like a change in temp. Or a sensor not reading something right like oil pressure being to low, you can have your vechile scanned at a parts house or garage and they can tell you what is making the light come on, as far as the gas light staying on your fuel level sensor that reads how much fuel is in the tank could be bad and making the light stay on also check your fuses