Examinational:

• In short, and EVAP leak code signifies a problem somewhere in the evaporative emission control system (EVAP), and the fuel tank is part of this system.
• Oftentimes, drivers will refill their fuel tank and forget to tighten the cap, which may trigger a check engine light with an "EVAP" diagnostic code.
• This does not mean this code always points toward a fuel cap, but it is the best place to start.