Solving the P0440 Mystery on Your 2022 Mercedes-Benz E-Class
Your 2022 Mercedes-Benz E-Class (W213) has set a P0440 — an EVAP system malfunction. The E 350 (2.0L turbo, 255 hp) and E 450 (3.0L inline-six, 362 hp) both use Mercedes's EVAP system with a leak detection pump. With a few years of service, certain components may need attention. Let's investigate.
Symptoms
- Check engine light on
- Faint fuel smell
- Slight MPG decrease
- Fueling difficulties
- Emissions test failure
Your E-Class drives normally. Engine, 9G-TRONIC, and 4MATIC are unaffected.
Most Likely Causes
- Fuel Filler Seal — Worn or loose. Estimated repair: $5–$35.
- Leak Detection Pump (LDP) — Mercedes EVAP diagnostic pump. Known failure. Estimated repair: $155–$380.
- Purge Valve (Regeneration Valve) — Controls vapor flow. Estimated repair: $120–$285.
- Shut-Off Valve — Controls EVAP venting. Estimated repair: $130–$305.
- Vapor Line Issue — Cracks or loose connections. Estimated repair: $55–$170.
Diagnostic Steps
- Check fuel filler, clear code, drive 50+ miles
- Scan with XENTRY or Star Diagnostic
- Test LDP, purge valve, and shut-off valve
- Smoke test if needed
- Check for W213-specific TSBs
Repair Costs
- Fuel filler: $5–$35
- LDP: $155–$380
- Purge valve: $120–$285
- Shut-off valve: $130–$305
- Vapor line: $55–$170
- Diagnostic: $100–$185
Warranty: Check your mileage — Mercedes's 4-year/50,000-mile warranty may still apply.
Can I Drive With P0440?
Yes. No performance or safety concerns.
DIY Feasibility
Moderate DIY difficulty. The LDP and purge valve are accessible but Mercedes-specific diagnostics help greatly. Independent Mercedes specialists save 25-35% over dealer pricing.