P0174 Ford Explorer
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 Explorer 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 Explorer.
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 Explorer.
Common Causes on Ford Explorer
- Intake manifold runner control valve leak on 3.5L V6
- PCV valve failure on passenger side of 2.3L EcoBoost or 3.5L V6
- Cracked vacuum hose at bank 2 fuel rail
- Mass airflow sensor contaminated or failing
- Bank 2 exhaust manifold gasket leak
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 Explorer
Explorer 3.5L EcoBoost and 2.3L EcoBoost are both prone to charge pipe and PCV issues causing lean codes on bank 2.