Tracking P0456 on Your 2021 Sonata
Your 2021 Sonata (8th generation, DN8) has flagged P0456—a very small EVAP leak. The 2.5L MPI, 1.6L turbo, or 2.5L turbo (N Line) uses a standard EVAP system with threaded gas cap. Well within Hyundai's 5yr/60k warranty.
Clues
- Check engine light on
- P0456 stored
- No performance issues
- All driving modes normal
Causes
- Gas Cap Seal (High Likelihood): Loose or worn. $0 warranty.
- Purge Control Solenoid Valve (High Likelihood): Standard EVAP failure. $0 warranty.
- Canister Close Valve (Medium Likelihood): Vent control. $0 warranty.
- EVAP Hose (Medium Likelihood): Connection issue. $0 warranty.
- FTP Sensor (Low Likelihood): Sensitivity. $0 warranty.
What to Do
- Reseat gas cap
- Schedule warranty appointment—Hyundai 5yr/60k through 2026
- Free diagnosis and repair
Cost
- Under warranty: $0 (5yr/60k through 2026)
- Federal emissions: through 2029
Can I Drive?
Yes. P0456 has zero impact on the Sonata's performance, including the 290-hp N Line turbo.
Warranty
Hyundai's 5yr/60k through 2026. 10yr/100k powertrain. Federal emissions 8yr/80k through 2029. You're covered.