INDEPENDENT REFERENCE
P0174 — System too lean (bank 2)
Generic powertrain DTC · MEDIUM priority for follow-up (not a certified safety rating)
What the code means
The fuel-control system identifies a persistently lean condition on bank 2.
What you might notice
Uneven idle; hesitation; increased fuel correction.
Possible causes — not a diagnosis
Vacuum leaks; low fuel pressure; contaminated MAF; exhaust leaks.
Useful diagnostic checks
Compare fuel trims between banks; inspect common intake leaks and fuel delivery.
Next steps
Repair validated air or fuel delivery faults and verify trims after repair.
Related OBD-II codes
These generic definitions are explanatory summaries of commonly standardized OBD-II powertrain conditions. Vehicle-specific code logic and service procedures must be verified against manufacturer documentation. EPA: On-board diagnostics.