Investigating P0446 on Your 2020 Dodge Challenger
A P0446 code on your 2020 Dodge Challenger points to an EVAP vent control circuit malfunction. The Challenger's LC/LA platform uses Stellantis' NVLD (Natural Vacuum Leak Detection) system, whether you're running the 3.6L Pentastar V6, 5.7L HEMI V8, 6.4L Scat Pack, or supercharged Hellcat. The NVLD monitors EVAP integrity through vacuum decay rather than pressurization.
The basic warranty (3yr/36k) has expired, but the federal emissions warranty (8yr/80k) likely still covers EVAP components through 2028. Check your mileage to confirm.
Clues and Symptoms
- Check engine light with P0446 stored
- Fuel fill issues at the pump
- EVAP readiness monitor not completing
- Possible fuel vapor odor
Top Suspects
- NVLD Switch/Seal Failure (High Likelihood): The NVLD unit's internal switch or seal degrades, triggering circuit faults. Replacement costs $150–$280.
- Purge Solenoid Malfunction (High Likelihood): The purge solenoid sticks, disrupting EVAP flow and triggering vent circuit errors. HEMI engines produce significant fuel vapors that stress this component. Replacement runs $120–$240.
- NVLD Wiring Corrosion (Medium Likelihood): Underbody-mounted connector exposed to road spray and debris. Repair costs $80–$180.
- Charcoal Canister Saturation (Medium Likelihood): High-displacement HEMI engines generate more fuel vapors, potentially saturating the canister. Replacement runs $220–$400.
- Gas Cap Seal (Low Likelihood): Worn seal allowing air ingress. Replacement is $10–$25.
How to Investigate
Start with a full code scan. The NVLD system requires wiTECH diagnostics for commanded testing—generic OBD-II scanners can read the code but can't test NVLD function. Inspect the gas cap seal first, then check the NVLD connector under the vehicle for corrosion.
Warranty and Cost
The basic warranty has expired, but the federal emissions warranty (8 years/80,000 miles) covers EVAP through 2028. Under 80k miles? A Dodge dealer should handle it free. Otherwise, expect $120–$400 out of pocket.
Safe to Drive?
Yes. P0446 has zero effect on your Challenger's engine performance, HEMI power, transmission, or any driving systems. Full performance is maintained.