Code dictionary Generic OBD-II
P0171System Too Lean Bank 1
This is a definition, not a repair instruction. It does not identify a failed part or establish that a vehicle is safe to drive.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Separately researched
Vehicle-specific diagnosis
These guides address the exact vehicles and conditions in their sources. Select the guide that matches your vehicle.
Ford
2018 F-150 P0300 and P0171: when injectors are actually implicated
Follow the code and build-date branches before approving injector replacement.
Chevrolet / GMC
Colorado and Canyon P0171 + P0174: inspect connections, then calibration
A paired-code case for 2020–2021 LGZ trucks, with a defined path if faults return.
Chevrolet
Chevrolet Cruze P0171/P1101: the PCV leak and manifold valve check
Distinguish a leaking camshaft-cover diaphragm from the intake-manifold cause that can damage it.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT