Hi, I have a Hyndai Elantra and the engine light

Apparently so - P0501 is a speed sensor code,
FAILURE CONDITIONS The ECM will set a code and the Malfunction Indicator Lamp (MIL) will turn on if there is no vehicle speed sensor output signal for 20 seconds during two driving cycles when the following conditions are met: a. Open between fuse and wheel speed sensor (WSS) b. Open between WSS and GND c. Open between WSS and ECM d. Short to battery or GND between WSS and ECM e. Faulty WSS However, the other, P-456 is an EVAP system code: a. Fuel filler cap loose or missing b. Fuel filler cap o-ring missing or damaged c. Faulty or damaged fuel filler pipe d. Leaking, disconnected or plugged fuel vapor lines e. Fuel in lines due to faulty rollover valve, on-board refueling vapor recovery valve or stuck closed CCV f. Canister close valve clogged, stuck open or closed g. Improperly installed purge solenoid valve h. PSV stuck open or closed i. Faulty fuel tank pressure sensor j. Leaking canister or catch tank a. If any codes relating to FTPS, CCV or PSV circuits are present, do all repairs associated with those codes before proceeding with this troubles area. b. If DTC P0455 is stored and MIL is illuminated, before proceeding to evaporative system test and repair, verify whether the customer was running the engine during refueling. c. If an obvious cause for DTC P0455 is an engine running during refueling, erase the DTC P0455 using Hi-Scan and do not repair the evaporative system. However, the vehicle should be monitored to find reoccurrence of the concern which may come from actual evaporative system.