Check Engine Light After Gas Cap
A loose, damaged, or wrong gas cap can trigger EVAP leak codes after the car runs its tank-seal test.
1
Tighten the cap until it clicks and inspect the seal for cracks.
2
Drive normally for a few trips; some vehicles need multiple readiness checks before the light clears.
3
Scan for EVAP codes if the light stays on, especially P0455, P0442, P0440, P0446, or P0456.