What Does P0172 Mean on Your 2022 Infiniti QX60?
A P0172 code on your 2022 Infiniti QX60 means the engine control module (ECM) has detected that Bank 1 is running richer than the target air-fuel ratio. The 2022 QX60 is powered by a 3.5-liter naturally aspirated V6 (VR35DD) producing 295 horsepower, paired with a 9-speed automatic transmission. Bank 1 is the cylinder bank containing cylinder number 1.
The 2022 QX60 was completely redesigned and uses Nissan's VR35DD engine with direct injection, a significant upgrade from the previous generation's VQ35DE. Running rich means excess fuel in the combustion mixture, which reduces efficiency and can damage the catalytic converter.
Symptoms You May Notice
- Check engine light on
- Fuel economy below the rated 21/26 mpg
- Rough or uneven idle
- Black exhaust smoke
- Fuel smell from the exhaust
- Reduced power or hesitation
- Possible misfires on Bank 1
Common Causes of P0172 on the 2022 Infiniti QX60
- Dirty MAF Sensor - The mass airflow sensor can accumulate dust and oil film over time, causing it to underread airflow and trigger over-fueling.
- Leaking Fuel Injector on Bank 1 - The VR35DD uses direct injection at high pressures. A leaking injector adds unmetered fuel to the cylinder.
- Faulty Bank 1 Upstream O2 Sensor - A degraded oxygen sensor on Bank 1 provides incorrect readings to the ECM.
- Intake Manifold Leak or Gasket Failure - A vacuum leak near Bank 1 can confuse airflow calculations and affect fuel trim.
How to Diagnose P0172
- Scan all codes - Check for P0175 (Bank 2 rich), MAF, O2, or misfire companion codes.
- Review fuel trims - Negative Bank 1 LTFT beyond -10% confirms the rich condition.
- Clean the MAF sensor - Always the best first diagnostic step.
- Monitor O2 sensors - Check Bank 1 Sensor 1 response time and voltage range.
- Test fuel injectors - Check for leaks and proper flow on Bank 1.
- Inspect the intake manifold - Check for vacuum leaks and gasket integrity.
Repair Options and Cost Breakdown
- MAF Sensor Cleaning - $15-$30 DIY.
- MAF Sensor Replacement - $160-$350 parts and labor.
- Fuel Injector Replacement - $300-$650 per injector with labor.
- O2 Sensor Replacement - $200-$400 parts and labor.
- Intake Manifold Gasket - $200-$450 parts and labor.
Most P0172 repairs on the 2022 QX60 cost between $180 and $450. Infiniti parts are moderately priced compared to European luxury brands.
Can You DIY This Repair?
MAF sensor cleaning and air filter replacement are straightforward DIY jobs. O2 sensor replacement is possible with a sensor socket. The 2022 QX60 engine bay is well-organized for a midsize SUV. Fuel injector work on the direct injection system requires professional tools and expertise.
Prevention Tips
- Replace the engine air filter every 15,000-20,000 miles
- Use quality 87+ octane fuel from top-tier stations
- Add fuel system cleaner every 10,000 miles
- Follow the Infiniti maintenance schedule
- Address check engine lights promptly to protect catalytic converters