Nissan Altima · Diagnostic Trouble Code
P0171 — System Too Lean (Bank 1)
Quick overview of P0171 on your Nissan Altima. Read the full diagnosis guide, then find the repair guides for your vehicle below.
Repair guides that fix P0171
Nissan Altima
2019-2024 Nissan Altima — MAF Sensor Replacement
Cleaning and replacing the MAF sensor.
Nissan Altima
2013-2018 Nissan Altima — Fuel Pump Replacement
How to test fuel delivery when pressure is suspect.
Nissan Altima
2013-2018 Nissan Altima — PCV Valve Replacement
A stuck PCV valve is a classic lean-code cause.
Nissan Altima
2019-2024 Nissan Altima - 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.