What Does P0172 Mean on Your 2022 Buick Enclave?
A P0172 diagnostic trouble code on your 2022 Buick Enclave means the engine control module (ECM) has detected a rich air-fuel mixture on Bank 1. The 2022 Enclave is powered by a 3.6-liter naturally aspirated V6 engine producing 310 horsepower, paired with a 9-speed automatic transmission. Bank 1 is the cylinder bank that contains cylinder number 1.
The 3.6L V6 in the Enclave uses direct injection, which provides excellent fuel efficiency but introduces specific failure points that can cause a rich condition. Running rich means the engine is burning more fuel than the ideal 14.7:1 air-fuel ratio.
Symptoms You May Notice
- Check engine light on
- Reduced fuel economy below the rated 18/26 mpg
- Rough or shaky idle
- Black exhaust smoke on acceleration
- Strong gasoline smell at the tailpipe
- Sluggish throttle response
- Possible engine misfires
Common Causes of P0172 on the 2022 Buick Enclave
- Dirty or Faulty MAF Sensor - The mass airflow sensor is the number one cause. On the 3.6L V6, the MAF sensor can accumulate debris and oil film over time, causing inaccurate airflow readings.
- Leaking Fuel Injector - The direct injection system runs at very high pressures. A leaking Bank 1 injector allows excess fuel into the cylinder.
- Faulty Upstream O2 Sensor (Bank 1) - A sluggish or failing oxygen sensor on Bank 1 can send incorrect data to the ECM, causing over-fueling.
- Purge Valve Stuck Open - The EVAP purge valve, if stuck open, allows fuel vapor to be drawn into the intake continuously, enriching the mixture.
How to Diagnose P0172
- Scan for all codes - Check for P0175 (Bank 2 rich), EVAP codes, MAF codes, or O2 sensor codes.
- Review fuel trim data - Negative LTFT values on Bank 1 beyond -10% confirm the rich condition.
- Inspect the MAF sensor - Clean with MAF-specific cleaner and retest.
- Test the EVAP purge valve - Verify it opens and closes properly. A stuck-open valve is a common GM issue.
- Monitor O2 sensor data - Check Bank 1 Sensor 1 for slow response or stuck readings.
- Test fuel injectors - Check for leaking or sticking injectors on Bank 1.
Repair Options and Cost Breakdown
- MAF Sensor Cleaning - $12-$25 for spray cleaner. Simple DIY job.
- MAF Sensor Replacement - $120-$280 parts and labor.
- EVAP Purge Valve Replacement - $80-$200 parts and labor. A common and affordable fix.
- Fuel Injector Replacement - $250-$500 per injector with labor.
- O2 Sensor Replacement - $150-$300 parts and labor.
Most P0172 repairs on the 2022 Enclave cost between $100 and $350. GM parts are generally more affordable than European luxury brands.
Can You DIY This Repair?
Several P0172 fixes are DIY-friendly on the Enclave. Cleaning the MAF sensor takes about 10 minutes. Replacing the EVAP purge valve is a common DIY repair with plenty of online guides for GM vehicles. O2 sensor replacement is doable with a sensor socket. Fuel injector work is more involved due to the direct injection system and is best left to a professional.
Prevention Tips
- Replace the engine air filter every 15,000-20,000 miles
- Use quality gasoline from top-tier stations
- Add fuel system cleaner every 10,000 miles
- Keep up with scheduled maintenance per the GM Owner Center
- Address check engine lights promptly to prevent catalytic converter damage