What P0175 Means for Your 2022 Buick Enclave
The 2022 Buick Enclave is powered by the 3.6L LGX V6 engine producing 310 hp, paired with a 9-speed automatic transmission. When P0175 appears, the ECM has detected that bank 2 (rear cylinder bank on this transverse-mounted V6) is running richer than the 14.7:1 stoichiometric ratio. The LGX engine is shared with the Chevrolet Traverse and GMC Acadia, so common issues are well-documented across GM's lineup.
Symptoms You'll Notice
- Check engine light on the Enclave's instrument cluster
- Fuel economy below the rated 18/26 MPG
- Dark exhaust smoke during acceleration
- Rough or uneven idle quality
- Fuel smell from the exhaust
- Sluggish throttle response
Common Causes on the Enclave's 3.6L V6
1. Dirty or Failed MAF Sensor
The LGX V6's MAF sensor sits in the intake duct and measures incoming airflow for the ECM's fuel calculations. Contamination from dust, aftermarket oiled air filters, or general environmental exposure is the most common trigger for P0175. The Enclave's intake draws from behind the front fascia where road debris is common. Cleaning costs $10–$15; GM OEM MAF replacement runs $100–$220.
2. Upstream O2 Sensor Failure (Bank 2)
The bank 2 upstream oxygen sensor monitors exhaust gas composition from the rear cylinders. Over time or due to contamination, the sensor becomes sluggish, providing delayed feedback that keeps the ECM in a fuel-rich state. The Enclave's rear bank sensor is accessible from underneath the vehicle. Replacement costs $120–$260 at a Buick dealer, or $90–$190 at an independent GM shop.
3. Fuel Injector Problems
The LGX uses direct fuel injection, which means injectors operate at very high pressures. Carbon buildup on injector tips can alter spray patterns, and injector seals can develop leaks. GM has issued TSBs for certain injector issues on the LGX V6. Fuel system cleaning costs $120–$240; injector replacement runs $100–$180 per unit plus labor.
4. EVAP Purge Solenoid
GM vehicles commonly experience purge solenoid issues where the valve sticks open, allowing excess fuel vapor into the intake. This enriches the air-fuel mixture beyond the fuel trim correction range. The solenoid costs $30–$65 with $80–$150 in labor.
Diagnostic Steps
- Scan for all codes — EVAP codes alongside P0175 point to the purge solenoid
- Check fuel trim data — LTFT bank 2 below -10% confirms persistent rich correction
- Clean the MAF sensor as an inexpensive first step
- Monitor O2 sensor voltage on bank 2 — should oscillate between 0.1V and 0.9V
- Check fuel pressure at the rail — LGX spec is approximately 50–58 psi at idle
- Test the EVAP purge solenoid for proper operation
Can You Keep Driving?
Yes, for normal family driving. The Enclave is a three-row SUV used primarily for commuting and family transport. A rich condition won't leave you stranded, but it increases fuel costs and threatens the catalytic converters. The Enclave has three cats costing $600–$1,200 each. Get the code addressed within two weeks.
Repair Cost Reality
Buick dealer labor rates run $130–$175/hour — less expensive than German luxury brands but still above mainstream GM pricing. The Enclave shares its 3.6L V6 with the Traverse and Acadia, so parts are widely available from aftermarket suppliers at competitive prices. An independent GM specialist can handle P0175 diagnosis and repair at 20–30% less than the dealer.