you may not ever smell fuel with a leaky/loose fuel cap. it is something that is a common fault code, and is *usually* related to the fuel cap. it costs more to 'test' the cap than replace it, so i usually recommend replacing it.
the other code indicates a fault in one of the parts that control fuel purge. this may or may not be related to the other code, and i am not going to guess.
what i do know, though, is that the best way to check for a leak in the evap system is to find a shop that has a smoke machine. this will show leaks in the evap system much easier and allow the technician to better locate any faults.