P0171 means your engine is running lean on Bank 1 — the most common fix is cleaning the MAF sensor ($8, 10 minutes). This code sets when the PCM (engine computer) has added as much extra …

Dec 31, 2025 · Learn what's causing your engine to run too lean and triggering the P0171 code, and how to fix it before it leads to costly repairs.

P0171 or P0174 readings indicate too lean of a system in one of your cylinder banks. Learn common causes and solutions to these trouble codes.

P0171 means System Too Lean (Bank 1). Learn symptoms, common causes, how to diagnose fuel trims, and proven fixes for vacuum leaks, MAF, and fuel issues.

Mar 17, 2023 · What does the P0171 code mean? The P0171 code indicates that the oxygen (O2) sensor on bank 1 sent a signal to the engine control module that the air-fuel mixture is too lean to be …

A P0171 code, “System Too Lean (Bank 1),” means your engine is running with too much air or too little fuel, triggering the check engine light and risking damage if ignored. This guide covers the P0171 …

Jul 15, 2024 · DTC P0171 signals that Engine Bank 1 is getting too much air or not enough fuel. Trouble spots include an oxygen sensor, vacuum leak, MAF sensor, or the fuel system (filter, pump, or …

Aug 19, 2024 · The P0171 diagnostic trouble code indicates that the fuel system is running lean on bank 1 of the engine. This means that there is an imbalance in the air-fuel mixture being delivered to the …

Details on causes of DTC P0171 and troubleshooting steps. Common fixes include cleaning the MAF sensor and repairing for vacuum leaks.

Apr 11, 2025 · Code P0171, officially designated as “System Too Lean (Bank 1)” by the Society of Automotive Engineers, signals that your engine’s air-fuel mixture contains too much air and …