Investigating P0446 on Your 2022 Audi A6
A P0446 code on your 2022 Audi A6 indicates an EVAP vent control circuit malfunction. The C8-generation A6 uses the 2.0L TFSI turbo (45 TFSI) or 3.0L TFSI turbo V6 (55 TFSI) on the MLB Evo platform. The EVAP system features an activated charcoal canister shut-off valve and the N80 purge regulator valve—a documented weak point across VW/Audi platforms.
The basic warranty (4yr/50k) may still be active. Check your purchase date and mileage.
Clues and Symptoms
- Check engine light with P0446
- Fuel fill difficulty
- EVAP readiness monitor incomplete
- Possible fuel vapor odor
Top Suspects
- Activated Charcoal Canister Shut-Off Valve Failure (High Likelihood): The vent shut-off valve fails electrically or mechanically. Replacement costs $170–$310 if not warranty-covered.
- N80 Purge Regulator Valve Malfunction (High Likelihood): Known VW/Audi weak point across MLB Evo platforms. Replacement runs $150–$270.
- Shut-Off Valve Wiring or Connector (Medium Likelihood): Connector corrosion or harness damage. Repair costs $90–$200.
- Plastic EVAP Component Deterioration (Medium Likelihood): Brittle plastic components common on Audi. Repair runs $80–$200.
- Gas Cap Seal (Low Likelihood): Worn seal. Replacement is $15–$40.
How to Investigate
Use VCDS/VAG-COM for dealer-level diagnostics or have a dealer use ODIS. Check the N80 purge valve first—it's the most common VAG EVAP failure. Inspect the canister shut-off valve connector for corrosion or damage.
Warranty and Cost
The basic warranty (4yr/50k) may apply. The federal emissions warranty (8yr/80k) covers EVAP through 2030. Out of warranty: $150–$310.
Safe to Drive?
Yes. P0446 doesn't affect your A6's engine performance, quattro AWD, transmission, or executive driving refinement.