2004 Ford F-150 engine smells like gas inside CAB

Have you had the codes read yet? Autozone tests for free, get the printout, and post the codes here. Also if fuel related, Autozone can rent you a fuel pressure tester, read the pressure, then remove the vacuum hose to the pressure regulator, apply a bit of vacuum to the regulator, any change in engine speed? Pressure? Now pinch the fuel return line, any increase in pressure? If not change the regulator.
Your purge cannister may be full of gas. If any gas is in it, replace it and repair the pressure problems and return line.