P0442 on Your 2024 Infiniti Q50
Your 2024 Infiniti Q50 has set code P0442, indicating the engine control module detected a small leak in the evaporative emission control system. This sealed system captures fuel vapors and channels them from the tank through a charcoal canister into the 3.0L twin-turbo V6 for combustion. A leak of roughly 0.020 inches was detected during the system's automated overnight monitoring.
Tracking the Leak
On a low-mileage 2024 Q50, the causes lean toward manufacturing and assembly factors:
- Gas cap seating issue (33%) — A cap that wasn't fully tightened after fueling, or one with debris on the seal. The simplest and most common trigger even on new vehicles.
- Canister vent control valve defect (27%) — A factory unit with borderline seal performance that passes initial quality checks but fails the system's sensitive leak monitoring after some drive cycles.
- EVAP connection gap (18%) — A vapor line quick-connect or clamp that wasn't fully seated during assembly. The Q50's sport sedan layout routes EVAP lines in tighter spaces.
- PVCV imperfection (13%) — The Purge Volume Control Valve may have an internal seat defect allowing minor vapor bypass when closed.
- Leak detection pump issue (9%) — The Nissan/Infiniti leak detection pump may have a calibration variance causing false positive readings.
What To Do
- Try the gas cap — Remove, inspect, and reseat firmly. Give it 2-3 drive cycles to see if the code clears.
- Go to Infiniti — This is a warranty repair on a 2024 model. The dealer will use CONSULT diagnostics and a smoke test to identify the leak at no cost.
Cost Reference (Warranty-Covered)
- Gas cap: $15–$35
- Canister vent control valve: $155–$300 installed
- EVAP line repair: $90–$230
- PVCV: $155–$290 installed
- Leak detection pump: $210–$400 installed
Warranty Coverage
Your 2024 Q50 is fully covered by Infiniti's 4-year/60,000-mile basic warranty and 6-year/70,000-mile powertrain warranty. EVAP components also fall under the federal emissions warranty (8 years/80,000 miles). This repair costs you nothing at the dealer.