Ford F-150 · Diagnostic Trouble Code
P0171 — System Too Lean (Bank 1)
Quick overview of P0171 on your Ford F-150. Read the full diagnosis guide, then find the repair guides for your vehicle below.
Repair guides that fix P0171
Ford F-150
2015-2020 Ford F-150 — MAF Sensor Replacement
Cleaning and replacing the MAF sensor.
Ford F-150
2015-2020 Ford F-150 — Fuel Pump Replacement
How to test fuel delivery when pressure is suspect.
Ford F-150
2015-2020 Ford F-150 — PCV Valve Replacement
A stuck PCV valve is a classic lean-code cause.
Ford F-150
2021-2024 Ford F-150 — Engine Air Filter Replacement
A restricted air filter can skew the air-fuel mixture.
General diagnostic information, not a factory service procedure. If you're unsure, have a qualified technician confirm the diagnosis before buying parts.