P0442 Hyundai Sonata
EVAP System Leak Detected (Small Leak) · Powertrain Code · Low · Repair: Easy
What is P0442?
A small leak has been detected in the EVAP system. Common causes include a loose or cracked gas cap, cracked EVAP hose, or faulty purge/vent valve.
When the Hyundai Sonata triggers code P0442 (evap system leak detected (small leak)), it typically points to an issue in the powertrain system. Below you'll find the most common causes, symptoms, and repair options specific to the Hyundai Sonata.
This repair is rated easy, meaning basic tools, no lift needed.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Hyundai Sonata.
Common Causes on Hyundai Sonata
- Gas cap not sealing properly
- EVAP purge valve leaking internally
- Fuel filler neck seal deterioration
- Small crack in EVAP vapor line
- Charcoal canister vent valve slow leak
Symptoms
- Check engine light illuminated
- Faint fuel smell near vehicle
- Slightly reduced fuel economy
- Failed emissions test
- Occasional rough idle after refueling
Notes for Hyundai Sonata
Hyundai and Kia EVAP purge valves and fuel filler neck seals are the most common causes of P0442 on Elantra, Sonata, Forte, and K5.