P0442 on a Hyundai: Causes, Fixes & Repair Cost

🟢 Low severity · drivable

Safe to drive — this is an emissions leak, not a mechanical issue — but fix it before your next emissions test.

What P0442 means on a Hyundai

On a Hyundai, P0442 means the engine computer found a small leak in the evaporative emission (EVAP) system that holds fuel vapors from the tank. Hyundai monitors tank pressure to catch exactly this kind of small leak. The car usually drives and performs normally.

Is P0442 common on Hyundais?

P0442 is very common on Hyundais, and a loose or worn gas cap is by far the most frequent trigger on this brand. As the car ages, cracked EVAP hoses and a failing purge or vent valve become more likely. It is an emissions fault, not a drivability fault.

Commonly reported on: Elantra, Sonata, Tucson, Santa Fe.

Symptoms

Check engine light on
Possible faint fuel smell
No drivability symptoms

Common causes

most common: Loose, missing, or worn gas cap
common: Cracked or disconnected EVAP hoses
common: Faulty purge or vent valve
less common: Small leak in the charcoal canister

How to fix it

Fix	DIY?	Typical cost
Tighten or replace the gas cap	Yes	$10–30
Replace cracked EVAP hoses	Yes	$20–80
Smoke test the EVAP system to find the leak	Mechanic	$50–150
Replace the purge or vent valve	Yes	$50–140