P0171 Ford Maverick
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 Ford Maverick 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 Ford Maverick.
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 Ford Maverick.
Common Causes on Ford Maverick
- PCV valve failure on 2.0L EcoBoost causing vacuum leak and lean condition
- Intake manifold gasket seepage on 2.5L Atkinson-cycle hybrid engine
- MAF sensor contamination from oil vapor on 2.0L EcoBoost with PCV issue
- Charge air cooler pipe clamp loosening on 2.0L turbo from engine vibration
- EVAP purge valve stuck open dumping excess air into intake manifold
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 Ford Maverick
A stuck-open EVAP purge valve is an often-overlooked cause of lean codes on Maverick.