Tracking P0456 on Your 2022 C-Class
Your 2022 C-Class (W206—first year of the new generation) has triggered P0456—a very small EVAP leak. The M254 2.0L turbo uses Mercedes's leak detection pump and activated charcoal filter. Mercedes-Benz 4yr/50k warranty runs through 2026.
Evidence
- Check engine light on
- P0456 stored
- No performance symptoms
- Fuel filler area may need cleaning
Suspects
- Fuel Filler Seal (High Likelihood): Debris or wear. $0 warranty or $15–$35.
- Leak Detection Pump (High Likelihood): First-year platform component. $0 warranty or $280–$500.
- Purge Valve (Medium Likelihood): Turbo heat cycling. $0 warranty or $180–$380.
- EVAP Hose (Medium Likelihood): Connection. $0 warranty or $160–$320.
- Activated Charcoal Filter (Low Likelihood): Premature degradation. $350–$600.
Diagnostic Steps
- Clean fuel filler area
- Check warranty—Mercedes 4yr/50k through 2026
- Mercedes dealer—STAR diagnostics
- First-year W206—ask about TSBs/calibration updates
Costs
- Under warranty: $0
- Fuel filler seal: $15–$35
- Leak detection pump: $280–$500
- Purge valve: $180–$380
Can I Drive?
Yes. P0456 has zero impact on the M254 turbo, 4MATIC, or performance.
Warranty
Mercedes-Benz 4yr/50k through 2026. Federal emissions 8yr/80k through 2030. First-year W206—ask about TSBs.