P0175 on the 2023 GMC Yukon
The 2023 GMC Yukon continues with GM's Gen V small-block V8 options — the 5.3L L84 (355 hp) or the 6.2L L87 (420 hp). Both feature Dynamic Fuel Management, direct fuel injection, and variable valve timing. Bank 2 on these V8 engines is the passenger side, containing cylinders 2, 4, 6, and 8. P0175 indicates the ECM has detected that Bank 2 is running too rich for normal fuel trim corrections.
At 1-3 years old with typically 15,000-45,000 miles, the 2023 Yukon is relatively new but not immune to sensor contamination and early wear.
Symptoms
- Check engine light on
- Fuel economy below 15-22 MPG expected
- Rough idle
- Rich exhaust smell
- Black soot on dual exhaust tips
- DFM operation may feel unsmooth
- Subtle power reduction
Causes
1. MAF Sensor Contamination — High Likelihood
Even at moderate mileage, PCV oil vapor contamination begins affecting MAF sensor accuracy on GM's direct injection V8 engines. The 2023 Yukon's large-displacement engines draw significant air volumes, making MAF accuracy critical. Contamination that causes a 5% underreading leads to a measurable rich condition across four Bank 2 cylinders.
2. O2 Sensor Issue — Medium Likelihood
A factory defect or early degradation of the Bank 2 upstream O2 sensor can cause inaccurate mixture feedback. GM V8 exhaust temperatures are high, and even new sensors can have quality variations. Comparing Bank 1 and Bank 2 sensor data identifies asymmetric performance.
3. EVAP Purge Valve — Medium Likelihood
GM's EVAP purge valve is a known weak point across the lineup, including newer models. A valve that sticks open at any mileage feeds continuous fuel vapors into the intake. This is one of the cheapest possible fixes for P0175 and worth checking early.
4. GDI Injector or Software Issue — Low Likelihood
On a newer 2023 model, injector issues are less likely but possible. GM may also have released ECM software updates that adjust fuel delivery or sensor thresholds. The dealer can check for applicable technical service bulletins.
Diagnostic Steps
- Scan for all codes with a GM-compatible scanner
- Compare fuel trims between banks at idle and 2,000 RPM
- Test MAF sensor output against specifications
- Monitor O2 sensor response
- Check EVAP purge valve
- Ask dealer about software updates
Repair Costs
- MAF sensor: $100–$260
- O2 sensor: $120–$300
- EVAP purge valve: $50–$150
- Software update: $0–$150
Most repairs should be covered under GM's 3-year/36,000-mile warranty.
DIY vs Dealer
If under warranty, use the dealer. The Yukon's spacious engine bay makes MAF sensor and EVAP purge valve replacement easy DIY jobs for out-of-warranty vehicles. O2 sensor and injector work are better handled by professionals.