Check Engine Light Stays on?

No there is no separate fuse for that light. If its not lighting up for the bulb check (when you first start it) then the bulb is either blown or missing. Some "dirty" sellers / car lots will actually take out the bulb if the engine light remains on so that the buyer will not see the check engine light on.

You will have to remove the instrument cluster. i have posted the correct removal and installation steps below. once out, just twist the bulb to remove it and replace it.

If check engine light on and blinking need to check it for a tune up
to best help in your issue have to get the truck scanned for codes

smell of gas :leaking injector, bad fuel line, bad coil, fuel regulator.

It is going to turn brown, that's normal. Does it smell burnt or have any shiny, metal flakes in it? If not then it's fine. Have the check engine codes scanned at a local auto part store, most do it for free. Post the code(s) you get and I will follow up.