After I parked the car there's no leak or anything. It smells like gas.

The evaporative emissions system on all modern cars captures, contains and disposes of gasoline fumes to protect the environment. The evap system is supposed to be air tight. If you are smelling gas, there is a leak in the system somewhere. To find the leak, we "smoke test" the evap system by introducing pressurized smoke and closely watching for smoke to escape. Evap leaks are most often inexpensive to fix, usually a rubber hose or connector. Repairs may get more expensive if the leak is on top of the fuel tank requiring tank removal; or, if the problem turns out to be a the charcoal canister or the roll over protection valve. Diagnosing the problem should take about 1 hour and should be scheduled in advance because it requires lifting the car on a rack. Thanks. Dave.