Investigating the P0440 on Your 2022 Acura RDX
The P0440 code on your 2022 Acura RDX indicates an EVAP system malfunction detected by the PCM. Your compact luxury SUV with the 2.0-liter turbocharged engine uses Honda/Acura's proven EVAP architecture. Let's investigate the cause.
The RDX EVAP System
Your 2022 RDX with the 2.0L turbo four-cylinder uses Honda/Acura's EVAP components:
- Purge Control Solenoid Valve (PCSV) — Controls fuel vapor flow from the canister to the turbo engine's intake
- Bypass Solenoid Valve — Honda-specific vapor flow routing component
- Canister Vent Shut Valve — Seals the system for leak testing
- Charcoal Canister — Activated carbon vapor storage
- FTP Sensor — Fuel Tank Pressure sensor for leak detection
- Fuel Filler Cap — Twist-on with rubber gasket
Ranked Suspects
- Gas Cap Seal (29%) — Gasket wear after 2–3 years. Cost: $12–$25.
- Purge Control Solenoid Valve (24%) — Most common mechanical failure. The turbo engine's heat accelerates wear. Cost: $35–$70, $105–$240 with labor.
- Bypass Solenoid Valve (16%) — Honda-specific component. Cost: $40–$80, $115–$250 with labor.
- Canister Vent Shut Valve (13%) — Sealing failure. Cost: $38–$75, $105–$240 with labor.
- EVAP Hose Issues (10%) — Turbo heat and age. Cost: $10–$35, $75–$180 with labor.
- FTP Sensor (5%) — In-tank pressure sensor. Cost: $45–$100, $120–$260 installed.
- Charcoal Canister (3%) — Overfilling saturation. Cost: $85–$210, $180–$370 installed.
Diagnostic Steps
- Gas Cap — Inspect, clean, reseat or replace. Clear code and monitor.
- Companion Codes — P0441, P0442, P0446, P0497 (low purge flow — Honda-specific).
- PCSV Test — Engine bay, test with 12V and vacuum pump.
- Bypass Solenoid — Use HDS or compatible tool to command and verify.
- Smoke Test — $80–$150 at a shop.
Warranty and DIY
Warranty: Acura's 4-year/50,000-mile warranty may still cover your 2022 RDX. The 6-year/70,000-mile powertrain extends further. Verify first.
For DIY, the RDX's 2.0T engine bay is compact but manageable for purge valve access.
The Verdict
Your 2022 RDX's P0440 is most likely a gas cap or PCSV issue. Honda/Acura's EVAP system is reliable — expect a one-time fix. Check warranty status before paying out of pocket.