After refuling at gas station it's hard to start

There is a problem within the evaporative emissions control system (EVAP) that is preventing proper fuel tank vapor venting which in turn is actually flooding the engine while refilling - holding the accelerator pedal to floor while cranking will help UNTIL repairs can be completed.. There are a couple of possibilities that will require *hands-on* testing to determine the actual failure. Professional scan testing is highly recommended as the scan tool also has the capability of performing functional testing of the suspected components involved.