Why does my Hyundai Elantra show a check engine light due to a loose fuel cap?

Home > Gari Forums > Hyundai Forums > Hyundai Elantra Forums > Hyundai Elantra Cracked o r Loose Fuel Cap Forums

Why does my Hyundai Elantra show a check engine light due to a loose fuel cap?

I own a 2021 Hyundai Elantra in Pakistan, and the check engine light sometimes comes on. My mechanic says it’s due to a loose fuel cap. Is this a known issue with Elantra, and why does a simple fuel cap cause this warning?

Gari Specialist asked on 04 Jul 2025 16:08:59 pm

1 Answer

19 views |

Gari Master - on 04 Jul 2025 16:22:49 pm

The Hyundai Elantra, like many modern cars, has an EVAP Evaporative Emission Control system that monitors fuel vapors. A loose o r improperly sealed fuel cap can cause a leak in this system, triggering the check engine light.
This is not a defect but a built-in safety and emission feature. In Pakistan, bumpy roads o r improper closing of the cap can easily cause it to loosen. If this happens:

Remove and re-tighten the cap until it clicks.

Drive for a few cycles start/stop, and the light may go off automatically.
If it doesn’t go away, get a diagnostic scan OBD-II to confirm the exact issue.