P0171 Honda Cr-V
System Too Lean (Bank 1) · Powertrain Code · High · Repair: Easy
What is P0171?
The engine is running lean on bank 1 — too much air or not enough fuel. Common causes include vacuum leaks, weak fuel pump, clogged fuel injectors, or a faulty MAF sensor.
When the Honda Cr-V triggers code P0171 (system too lean (bank 1)), 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 Cr-V.
This repair is rated easy, meaning basic tools, no lift needed.
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 Cr-V.
Common Causes on Honda Cr-V
- Intake manifold gasket leak on 1.5L turbo CR-V or 3.5L V6 Pilot causing lean condition
- PCV valve failure on 1.5L turbo CR-V creating vacuum leak and oil contamination
- MAF sensor contamination from fuel dilution oil mist on 1.5T CR-V (2017-2020)
- Cracked intake air tube between air filter and throttle body on 3.5L Pilot
- EVAP purge valve stuck open on CR-V allowing unmetered air into intake
Symptoms
- Rough or unstable idle speed
- Hesitation or stumble during acceleration
- Engine surging or hunting at idle
- Lean misfire under load causing jerking
- Poor acceleration response and reduced power
- Check engine light illuminated
Notes for Honda Cr-V
The 2017-2020 CR-V 1.5T fuel dilution issue contributes to MAF contamination and lean codes.