Investigating the P0440 Code on Your 2020 Dodge Charger
The P0440 code on your 2020 Dodge Charger signals a malfunction in the evaporative emission control (EVAP) system. Whether you're running the 3.6L Pentastar V6, 5.7L HEMI, 6.4L HEMI Scat Pack, or the supercharged 6.2L Hellcat, the EVAP system shares the same architecture and diagnostic approach.
The Charger's EVAP System
Your LD-platform Charger uses Stellantis' EVAP design with the distinctive NVLD leak detection:
- NVLD (Natural Vacuum Leak Detection) Module — Stellantis' passive approach that monitors natural fuel tank vacuum during cooldown to detect leaks
- Purge Solenoid Valve — Engine bay-mounted, controls fuel vapor flow from the canister to the intake manifold
- Vent Valve — Near the charcoal canister, controls atmospheric entry and seals for testing
- Charcoal Canister — Stores fuel vapors, mounted near the fuel tank area
- Fuel Filler Cap — Traditional screw-on cap with rubber gasket on most Charger trims
Ranked Suspects
- Gas Cap Seal Wear (28% of cases) — After 4–5 years, the rubber gasket hardens and cracks. Cost: $10–$22.
- NVLD Module Failure (22%) — The NVLD switch degrades over time with temperature cycling and moisture exposure. Cost: $35–$80, $100–$230 with labor.
- Purge Solenoid Valve (20%) — HEMI engines in particular generate significant underhood heat that stresses the purge valve. Cost: $25–$60, $90–$210 with labor.
- EVAP Hose Deterioration (14%) — Heat and age degrade rubber vapor lines, especially near the engine. High-performance variants produce more heat. Cost: $10–$40, $75–$190 with labor.
- Vent Valve Failure (10%) — Undercarriage exposure to road conditions. Cost: $30–$65, $90–$220 with labor.
- Charcoal Canister Saturation (6%) — Fuel overfilling or long-term vent valve failure. Cost: $80–$200, $170–$350 installed.
Diagnostic Investigation
- Replace the Gas Cap — $10–$22, the cheapest and fastest first step. Clear the code and monitor for 2–3 drive cycles.
- Scan for Companion Codes — Use an OBD-II scanner or Stellantis-specific tool. Check for P0441 (purge flow), P0442 (small leak), P0456 (very small leak).
- Test the NVLD Module — Located near the charcoal canister. Check the electrical connector for corrosion and verify vacuum switch function.
- Purge Valve Check — Engine bay, listen for clicking, test resistance (should be 20–30 ohms).
- Smoke Test — The definitive leak finder. $80–$150 at a shop.
DIY Feasibility
The 2020 Charger is out of the 3-year/36,000-mile basic warranty. For DIY:
- Gas cap: No tools needed
- Purge valve: Moderate — accessible from engine bay, 30–45 minutes. On HEMI models, clearance may be tighter.
- NVLD module: Moderate — requires getting under the vehicle, 30–45 minutes
- Vent valve: More involved — undercarriage access needed
The Verdict
Your 2020 Charger's P0440 most likely traces to a gas cap, NVLD module, or purge valve. Start with the cap, then let companion codes guide deeper investigation. The Charger's EVAP system is the same regardless of engine — the HEMI V8 and Pentastar V6 share identical EVAP components.