What does this code mean?
P0442 describes a small leak, P0455 a large leak and P0456 a very small leak. Check the correct fuel-cap seal where fitted, hoses, valves and the manufacturer's leak-test procedure. A loose cap is one possibility, not the only cause. Do not use compressed air or improvised flame tests around fuel vapour.
Sources and interpretation [1]
A code identifies a detected condition, not a part that must automatically be replaced.
Manufacturer wording
Source wording can vary by vehicle and suffix. It is shown as written, not as a universal diagnosis.
P0456Evaporative System (EVAP) - Very Small Leak storedP0456Evaporative System (EVAP) - Very Small LeakManufacturer communications
6Original wording in English
HYUNDAI
Reported code forms P0456
Certain 2011 2015 Sonata Hybrid vehicles (YF HEV) may experience check engine light illumination with Evaporative System (EVAP) leakage related DTC P0442 Small Leak, P0455 Large Leak or P0456 Very Small Leak stored.…
HYUNDAI
Reported code forms P0456
Certain 2011 2015 Sonata Hybrid vehicles (YF HEV) may experience a check engine light illumination with an Evaporative System (EVAP) leakage related DTC P0442 Small Leak, P0455 Large Leak, or P0456 Very Small Leak…
HYUNDAI
Reported code forms P0456
Certain 2016-2019 Sonata Hybrid (LF HEV) vehicles may experience check engine light illumination with DTC P0456 - Evaporative System (EVAP) - Very Small Leak stored. Salt particulate deposit can form inside the Natural…
HYUNDAI
Reported code forms P0456
Certain 2016-2019 Sonata Hybrid (LF HEV) may experience check engine light illumination with DTC P0456 - Evaporative System (EVAP) - Very Small Leak stored. These conditions primarily occur in the California coastal…
HYUNDAI
Reported code forms P0456
Some Veloster (FS) and Sonata Hybrid (YF HEV) vehicles may experience a check engine warning light ON with any of the following DTCs found stored: ? P0442 - Evaporative System (EVAP) - Small Leak ? P0455 - Evaporative…
HYUNDAI
Reported code forms P0456
Some Veloster (FS) and Sonata Hybrid (YF HEV) vehicles may experience a check engine warning light ON with any of the following DTCs found stored: ? P0442 - Evaporative System (EVAP) - Small Leak ? P0455 - Evaporative…
Check vehicle applicability
9A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Historical vehicle association; OBD-II compatibility is not established by this record.
| Make | Model | Model year |
|---|---|---|
| Hyundai | SONATA HYBRID | 2019 |
| Hyundai | SONATA HYBRID | 2018 |
| Hyundai | SONATA HYBRID | 2017 |
| Hyundai | SONATA HYBRID | 2016 |
| Hyundai | SONATA HYBRID | 2015 |
| Hyundai | SONATA HYBRID | 2014 |
| Hyundai | SONATA HYBRID | 2013 |
| Hyundai | SONATA HYBRID | 2012 |
| Hyundai | SONATA HYBRID | 2011 |
Historical records · 1 · Historical vehicle association; OBD-II compatibility is not established by this record.
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Sources and interpretation
These explanations are editorial summaries of the linked manufacturer material. PDF page numbers count from the first file page. Original publications are in English; translations are reference aids. A cited edition is not a claim that it is the manufacturer's latest instruction.
- 2024–2025 MY OBD System Operation Summary for Gasoline Engines ↗
Ford Motor Company · PDF page(s) 13, 14 ·
Source check date · 2026-10-27
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.