What Does P0172 Mean on Your 2024 Infiniti QX60?
A P0172 code on your 2024 Infiniti QX60 indicates the ECM has detected a rich air-fuel mixture on Bank 1. The 2024 QX60 is powered by the VR35DD 3.5-liter V6 producing 295 hp with a 9-speed automatic and available AWD. Bank 1 is the cylinder bank containing cylinder number 1.
Running rich means excess fuel relative to air in the combustion mixture. The ECM uses oxygen sensor data to control the air-fuel ratio and sets P0172 when corrections exceed normal limits.
Symptoms You May Notice
- Check engine light on
- Fuel economy below the rated 21/26 mpg
- Rough idle
- Black exhaust smoke
- Fuel smell from exhaust
- Reduced power
- Bank 1 misfires
Common Causes of P0172 on the 2024 Infiniti QX60
- Contaminated MAF Sensor - Dust and oil film reduce MAF accuracy, causing the ECM to over-fuel. The most common cause.
- Leaking Direct Fuel Injector - High-pressure injectors on the VR35DD can develop leaks on Bank 1.
- Failing Bank 1 O2 Sensor - A degraded upstream O2 sensor sends inaccurate data to the ECM.
- Intake System Leak - A vacuum leak near Bank 1 affects airflow calculations and fuel trim.
How to Diagnose P0172
- Scan all codes - Check for companion codes.
- Review Bank 1 fuel trims - Negative LTFT confirms the issue.
- Clean the MAF - Best first step.
- Monitor O2 sensors - Check Bank 1 response.
- Test injectors - Check Bank 1 for leaks.
- Inspect intake system - Check for vacuum leaks.
Repair Options and Cost Breakdown
- MAF Cleaning - $15-$30 DIY.
- MAF Replacement - $170-$360 parts and labor.
- Fuel Injector Replacement - $310-$670 per injector.
- O2 Sensor Replacement - $210-$420 parts and labor.
- Intake Gasket Repair - $200-$460 parts and labor.
Most repairs cost $180 to $470. Warranty coverage may apply for the 2024 model year.
Can You DIY This Repair?
MAF cleaning and air filter replacement are easy DIY tasks. O2 sensor replacement is possible with a sensor socket. The QX60 engine bay is well-organized. Fuel injector work on the direct injection system requires professional tools.
Prevention Tips
- Replace the air filter every 15,000-20,000 miles
- Use quality fuel from top-tier stations
- Add fuel system cleaner every 10,000 miles
- Follow the Infiniti maintenance schedule
- Address check engine lights promptly