P0174 Honda Accord
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 Honda Accord 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 Honda Accord.
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 Honda Accord.
Common Causes on Honda Accord
- Intake manifold gasket leak causing unmetered air entry
- PCV valve stuck open causing excessive crankcase ventilation
- Mass airflow sensor contamination
- Vacuum leak at brake booster check valve
- Fuel injector clogged or restricted
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 Honda Accord
P0174 is uncommon on 4-cylinder Civic and Accord models as they only have one bank. Only V6 Accord models (3.5L J35) will set this code.