P0174 Ford Bronco
System Too Lean (Bank 2) · Powertrain Code · High · Repair: Moderate
What is P0174?
The engine is running lean on bank 2. Same causes as P0171 but affecting the opposite cylinder bank on V-engines.
When the Ford Bronco triggers code P0174 (system too lean (bank 2)), it typically points to an issue in the powertrain system. This is a high severity code, so address it promptly to avoid further damage or safety concerns. Below you'll find the most common causes, symptoms, and repair options specific to the Ford Bronco.
This repair is rated moderate, meaning some experience and specialty tools required.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Ford Bronco.
Common Causes on Ford Bronco
- Charge pipe leak on 2.7L EcoBoost V6 bank 2 side
- PCV system failure on passenger side of engine
- Vacuum hose crack from off-road vibration and heat cycling
- Mass airflow sensor fouled from dust and water exposure
- Bank 2 fuel injector carbon buildup on direct injection
Symptoms
- Rough idle especially when cold
- Hesitation or stumble on acceleration
- Engine surging at steady throttle
- Lean misfire under load
- Poor fuel economy
- Check engine light illuminated
Notes for Ford Bronco
On Bronco 2.3L EcoBoost models, P0174 is uncommon as they only have one bank. The 2.7L V6 can develop bank 2 lean codes from charge pipe issues.