What Does P0456 Mean on Your 2020 Dodge Durango?
A P0456 code on your 2020 Dodge Durango means the PCM has detected a very small leak—approximately 0.020 inches—in the evaporative emission control system. Your Durango uses Stellantis's NVLD (Natural Vacuum Leak Detection) technology to monitor the sealed EVAP system with precision.
The 2020 Durango is available with the 3.6L Pentastar V6 or the 5.7L HEMI V8, both sharing the same EVAP system architecture. With five-plus years of service on your three-row SUV, age-related EVAP wear is increasingly likely.
Common Causes: Following the Trail
- Gas cap seal wear (30%) — Five years of family road trips and daily commuting have cycled that gas cap thousands of times. The rubber seal gradually loses its ability to maintain a vapor-tight seal.
- NVLD sensor malfunction (22%) — Stellantis's NVLD is the primary EVAP monitoring component and can develop internal faults with age and mileage.
- EVAP line deterioration (18%) — Five years of temperature cycling and road vibration can crack or loosen vapor lines, particularly along the frame rails.
- Purge valve seepage (15%) — The engine-bay purge solenoid may develop slight leak-through when closed.
- Charcoal canister damage (10%) — The canister's underbody location makes it vulnerable to road debris over years of driving.
- Fuel tank or filler seal (5%) — The fuel pump module gasket or filler neck seal can slowly degrade.
Diagnostic Steps
- Gas cap replacement — Try a new OEM-spec cap ($15–$30), clear the code, and drive for a week. This resolves roughly a third of P0456 cases.
- Visual EVAP inspection — Check all accessible vapor lines and connections for damage, particularly near the frame and exhaust heat sources.
- Smoke test — The most efficient way to find a tiny leak. Low-pressure smoke fills the system and escapes at the breach point.
- wiTech NVLD diagnosis — Stellantis's dealer tool provides real-time NVLD sensor data and system monitoring.
- Component-by-component check — Test the purge valve, vent valve, and NVLD sensor if the smoke test is inconclusive.
Repair Costs
- Gas cap: $15–$30 (DIY)
- NVLD sensor: $200–$400
- EVAP hose repair: $100–$250
- Purge valve: $150–$320
- Charcoal canister: $280–$550
Warranty and DIY Notes
Your 2020 Durango's basic warranty has expired, but the federal emissions warranty covers EVAP components for 8 years/80,000 miles through 2028. Check your mileage—you may still qualify. DIY feasibility is moderate; the gas cap is simple, but the Durango's size provides decent underbody access for visual inspections.