What P0174 Means on Your 2023 GMC Yukon
When your 2023 GMC Yukon sets a P0174 code, the ECM has detected that Bank 2 is running too lean. The 2023 Yukon offers the 5.3L V8 (355 hp), 6.2L V8 (420 hp), and 3.0L Duramax turbo-diesel. On the V8 engines, Bank 2 is the driver side. A lean condition means too much air or insufficient fuel on that bank's cylinders.
As a family hauler and capable tower, the Yukon needs its engine running at peak performance. Address this code promptly.
Symptoms
- Check engine light on
- Rough or unsteady idle
- Reduced acceleration power
- Increased fuel consumption
- Engine hesitation under load
- Possible engine knock
Common Causes
- Vacuum Leak (30% likelihood) – Intake manifold gaskets, vacuum lines, and PCV connections can develop leaks.
- Fuel Injector Issue (25% likelihood) – Clogged or malfunctioning injectors on Bank 2, potentially related to DFM carbon buildup.
- MAF Sensor Problem (25% likelihood) – Contaminated or defective mass airflow sensor.
- Exhaust Leak (20% likelihood) – Driver-side exhaust manifold gasket or bolt failure.
Diagnosis
- Check warranty coverage – The 2023 Yukon should still be under GM's bumper-to-bumper warranty.
- Compare bank fuel trims – Determine if the issue is bank-specific.
- Smoke test – Locate intake system leaks.
- Test injectors and MAF – Verify proper operation.
- Inspect exhaust manifolds – Check for leaks on Bank 2.
Repair Costs
- Vacuum leak – $80–$700.
- Fuel injector – $200–$550.
- MAF sensor – $80–$250.
- Exhaust manifold – $200–$800.
Under warranty, these repairs should be free at your GMC dealer.
Dealer or DIY?
With warranty coverage available, take it to the dealer first. They'll diagnose and repair at no cost, using GM tools and genuine parts.
Prevention
- Use Top Tier fuel consistently
- Follow GM's maintenance schedule
- Keep up with air filter changes
- Report drivability changes to the dealer early
- Consider fuel system cleaning at 50,000 miles