2017 Toyota Highlander Code P0171
2017 Highlander CEL AWD P0171 (bank 1) P0174 (bank 2) P1170 Jump to Latest 15K views 11 replies 6 participants last post by ClassyAndSassy Sep 3, 2025 J. The P0171 code for Toyota vehicles indicates that the fuel trim system on Bank 1 is too lean. This means that the engine is receiving too much air and not enough fuel, resulting in a lean air-fuel mixture.
This can lead to inefficient combustion, reduced engine performance, and potential damage to the engine if not addressed promptly. P0171 Is A System Too Lean (Bank 1) Code On Your Toyota, Which Is Triggered By The First Exhaust Oxygen (02) Sensor (a/k/a Upstream 02 Sensor) On The Bank 1 Side Of The Engine. 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 Definition: Fuel Trim System Lean Bank 1 P0171 is a generic code, meaning it has the same definition for the Toyota Highlander as any other vehicle. Fuel Trim System The ideal air/fuel ratio is 14.7:1 (14.7 parts air to one part fuel). Your vehicle's fuel trim system manages the air/fuel ratio and adjusts it when the powertrain control module determines it's necessary (it can range.
Toyota P0171 And P0174 codes indicate air. The P0171 and P0174 indicate a lean air-fuel mixture, often caused by vacuum leaks, faulty sensors, or fuel delivery issues. The P0171 lean code is one of the most common problems that can occur in Toyota vehicles.
When this code pops up, it indicates that the engine is running too lean or with an air/fuel mixture that contains too much air and not enough fuel. This extensive guide will provide a detailed look at what causes P0171, how to accurately diagnose the issue, repair costs, and step. Hello all, I recently got the System too Lean (Bank 1) P0171 error code and as per everyone's suggestion, I replaced the intake manifold with the new orange.
In this video, we go over the specific steps to diagnose and repair the P0171 System Too Lean Bank 1 trouble code. This is a very common issue on many vehicles including Ford, Chevy, and Toyota.