Code P0171 what it means and how to fix it
 
The OBD-II trouble code P0171 indicates a system too lean condition in the engine's air-fuel mixture on Bank 1. This means that there is an imbalance of air and fuel in the engine, resulting in too much air or too little fuel. This can lead to a variety of symptoms such as poor fuel economy, rough idling, and potential engine misfires. Here's what you can do to troubleshoot and fix the P0171 trouble code:
1. Inspection of Vacuum Leaks: Check for vacuum leaks in the engine using a smoke machine or by visually inspecting hoses, gaskets, and connections for any signs of wear, damage, or disconnection. Common areas to inspect include the intake manifold gasket, vacuum lines, PCV system, and the brake booster.
2. Check the Mass Airflow Sensor (MAF): Inspect the MAF sensor for dirt, debris, or damage. Cleaning the MAF sensor using MAF sensor cleaner may help if it's contaminated.
3. Examine the Oxygen Sensor: Check the upstream oxygen sensor (Bank 1, Sensor 1) for proper operation. A malfunctioning oxygen sensor can cause incorrect readings and contribute to a lean condition.
4. Inspect the Fuel System: Check the fuel system for issues such as clogged fuel injectors, fuel pressure problems, or a faulty fuel pump. These could lead to an insufficient fuel supply, contributing to the lean condition.
5. Check for Exhaust Leaks: Inspect the exhaust system for leaks that could result in false oxygen sensor readings.
6. Clearing the Code: After addressing any potential issues, use an OBD-II scanner to clear the trouble code.
It's important to note that troubleshooting and repairing trouble code P0171 can vary depending on the make and model of the vehicle. It is beneficial to diagnostic by one of our certified mobile mechanics with experience with diagnosing and repairing OBD-II trouble codes.