Diagnosing P0455 on Your 2020 Mercedes-Benz GLE
P0455 on your 2020 GLE (W167) means a large EVAP leak. This first-year W167 may still be under emissions warranty. Gas cap first, then consider the Mercedes Leak Detection Pump.
Symptoms
- Check engine light with P0455
- Fuel smell possible
- Gas cap worn
- Emissions test failure
Causes Ranked
- Gas Cap Seal (Very High Likelihood): Degraded. $15–$35.
- Leak Detection Pump (Medium Likelihood): Mercedes LDP. $300–$540 installed.
- EVAP Purge Valve (Medium Likelihood): Sticking. $220–$420 installed.
- Fuel Tank Vent Valve (Low-Medium Likelihood): Seal wear. $240–$440 installed.
- Vapor Line (Low Likelihood): Age cracking. $120–$300.
Warranty
Mercedes' 4yr/50k warranty may have expired. Federal emissions (8yr/80k) covers EVAP through 2028.
Safe to Drive?
Yes. P0455 doesn't affect engines, 4MATIC, AIRMATIC, or features.