What Does P0171 Mean on Your 2024 Infiniti Q50?
A P0171 code on your 2024 Infiniti Q50 indicates the engine control module detected a lean condition on Bank 1. The 2024 Q50 continues with the proven 3.0-liter twin-turbocharged V6 (VR30DDTT) producing 300 hp (Luxe) or 400 hp (Red Sport 400). Bank 1 is the rear cylinder bank. The ECM is compensating by adding more fuel to correct the lean air-fuel ratio.
Symptoms You Might Notice
- Check engine light on
- Rough idle in the normally refined twin-turbo V6
- Sluggish throttle response
- Fuel economy below the expected 20-29 MPG
- Reduced boost feel during acceleration
- Uneven power delivery at various RPMs
Common Causes of P0171 on the 2024 Infiniti Q50
Under warranty, most causes should be repaired at no cost:
- Boost or Charge Pipe Leak (30% likelihood) — Factory assembly issues with charge piping, intercooler connections, or coupler clamps in the twin-turbo system.
- ECM Software Calibration (25% likelihood) — Nissan/Infiniti may have released fuel management updates for the VR30DDTT engine.
- MAF Sensor Defect (25% likelihood) — A factory-defective or contaminated mass air flow sensor causing inaccurate readings.
- Fuel System Component (20% likelihood) — HPFP weakness, faulty injector, or fuel pressure sensor issue preventing proper fuel delivery.
How to Diagnose the Problem
- Visit your Infiniti dealer — The 2024 Q50 is under warranty. Let the dealer diagnose and repair for free.
- Request TSB check — Ask about Technical Service Bulletins for the VR30DDTT and lean codes.
- Independent diagnosis — Compare fuel trims on both banks using an OBD-II scanner.
- Boost leak testing — Professional intake pressurization to find hidden leaks.
- Live data analysis — Monitor MAF, fuel pressure, and O2 sensors during driving.
Repair Options and Cost Breakdown
- Boost or charge pipe repair: $150–$500. Warranty-covered on new vehicles.
- ECM software update: $0–$200. Free under warranty or TSB.
- MAF sensor replacement: $180–$400. Part cost $70–$180. Easy DIY if out of warranty.
- Fuel system repair: $500–$1,300. Covered under powertrain warranty.
Prevention Tips
- Use premium 91+ octane fuel as required
- Follow Infiniti's maintenance schedule
- Use Infiniti-recommended oil specifications
- Report performance changes to the dealer promptly
- Avoid aftermarket intake or exhaust modifications without proper tuning
Warranty Coverage
Your 2024 Infiniti Q50 is covered by a 4-year/60,000-mile bumper-to-bumper warranty and a 6-year/70,000-mile powertrain warranty. All engine, turbocharger, and fuel system components are included. Take it to your Infiniti dealer for free service.