EVAP leak
EVAP codes mean the vapor-recovery system failed a leak or purge test.
P0442 is a small leak, P0455 a large leak, and P0440 a general system fault. A loose fuel cap is a frequent, cheap cause of the large-leak code.
Tighten the cap, then rescan before replacing the canister or purge valve. The DTC pages list the usual vapor-system checks.
A trouble code marks a condition to test. It does not by itself prove which part to replace.