Investigating P0446 on Your 2022 Acura MDX
A P0446 code on your 2022 Acura MDX indicates an EVAP vent control circuit malfunction. The fourth-generation MDX (2022+) uses a 3.5L V6 (or 3.0L turbo V6 in the Type S). Acura's EVAP system uses a canister vent shut valve for vent control, built on Honda's proven architecture. Honda/Acura HDS diagnostics provide detailed EVAP testing capability.
The Acura basic warranty (4yr/50k) should still be active. The powertrain warranty (6yr/70k) provides coverage through 2028.
Clues and Symptoms
- Check engine light with P0446
- Fuel fill difficulty
- EVAP readiness monitor incomplete
- Possible fuel odor
Top Suspects
- Canister Vent Shut Valve Failure (High Likelihood): The vent shut valve is the primary P0446 component. Replacement costs $130–$250 if not warranty-covered.
- Bypass Solenoid Valve Malfunction (High Likelihood): Honda/Acura's purge valve can stick, disrupting EVAP flow. Replacement runs $120–$220.
- Vent Valve Wiring or Connector (Medium Likelihood): Connector corrosion or damage at the vent shut valve. Repair costs $80–$170.
- Charcoal Canister (Medium Likelihood): First-year redesign may have canister fit or routing issues. Replacement runs $200–$380.
- Gas Cap Seal (Low Likelihood): Worn seal—the #1 EVAP cause on Honda/Acura vehicles. Replacement is $12–$28.
How to Investigate
Scan all codes. An HDS scan at an Acura dealer provides canister vent shut valve and bypass solenoid commanded testing. For DIY, check the gas cap seal first—it's the most common EVAP trigger on Honda/Acura. Then inspect the vent valve connector.
Warranty and Cost
The basic warranty (4yr/50k) should be active. The powertrain warranty (6yr/70k) covers through 2028, and the federal emissions warranty (8yr/80k) through 2030. Under warranty, all repairs are free.
Safe to Drive?
Yes. P0446 doesn't affect your MDX's engine, SH-AWD system, transmission, towing capacity, or any luxury features.