What P0175 Means for Your 2024 Infiniti QX80
The 2024 Infiniti QX80 carries forward the proven 5.6L V8 (VK56VD) with 400 horsepower and a 7-speed automatic transmission. A P0175 code on this flagship SUV indicates that Bank 2 — the passenger-side cylinder bank on the longitudinally-mounted V8 — is running too rich. The ECM's fuel trim corrections have hit their limit trying to lean out the mixture, and it's flagging the issue for your attention.
How You'll Know Something's Wrong
- Check engine light illuminated
- Worse fuel economy than the already-modest 14 MPG combined rating
- Black exhaust smoke, especially noticeable on cold mornings
- Rough idle quality
- Fuel smell at the tailpipe
- Occasional stumble or hesitation
Likely Culprits
1. Contaminated MAF Sensor — High Likelihood
Even on a new 2024 model, the MAF sensor can become contaminated if an aftermarket oiled air filter is installed or if the vehicle is operated in extremely dusty environments. The VK56VD's MAF element is particularly sensitive, and even a thin film of oil or dust significantly throws off airflow readings, causing the ECM to over-fuel Bank 2.
2. Defective O2 Sensor (Bank 2 Upstream) — Medium Likelihood
While uncommon on a brand-new vehicle, manufacturing defects can affect any sensor. The Bank 2 upstream oxygen sensor on the QX80 sits on the passenger-side exhaust manifold. A sensor that reads falsely lean prompts continuous fuel enrichment from the ECM.
3. Fuel Injector Defect — Medium Likelihood
The VK56VD's dual-injection system (port + direct) means there are 16 total injectors. A manufacturing defect in any Bank 2 injector — whether port or direct — can cause a persistent rich condition. This is a warranty repair item on a 2024 model.
4. Fuel System Pressure Anomaly — Low Likelihood
An overperforming high-pressure fuel pump or a regulator holding pressure above spec can cause systemic rich running. If P0172 (Bank 1 rich) accompanies P0175, this becomes a stronger suspect.
Diagnostic Steps
- Scan for additional codes — Check if P0172 is also present, which would point to a shared-system issue.
- Review fuel trim data — Bank 2 LTFT above +15% at idle is abnormal and confirms the rich condition.
- Inspect the air intake — Check for an aftermarket oiled air filter, loose intake ducting, or a damaged air filter box.
- MAF sensor check — Compare live MAF readings at idle (should be around 8–12 g/s) to known-good values.
- O2 sensor test — Monitor Bank 2 upstream sensor for proper 0.1V–0.9V oscillation at 1–3 Hz.
Repair Costs
Given this is a 2024 model, warranty should cover most repairs. Out-of-warranty estimates for the QX80:
- MAF sensor cleaning: $10–$15 DIY
- MAF sensor replacement: $250–$475
- O2 sensor replacement: $300–$575
- Fuel injector replacement: $450–$850 per injector
- Fuel pump/regulator: $550–$1,000
Warranty Coverage
The 2024 QX80 includes a 4-year/60,000-mile basic warranty and a 6-year/70,000-mile powertrain warranty. A P0175 code caused by a defective sensor or injector should be covered under either warranty. Always visit an authorized Infiniti dealer first — don't pay out of pocket for what should be a warranty repair on a vehicle this new.
Safe to Drive?
Yes for short distances to the dealer, but don't delay. The QX80's catalytic converters are among the most expensive to replace ($2,500–$4,500 each), and rich running is the primary cause of premature converter failure.