why does my BMW X3 G01 (2018-2024) have a check engine light and P0171 code?

Solution

1. Preparation

• Gather necessary tools and components.
• Disconnect the battery before starting work.
• Ensure the engine is cool to prevent burns.

2. Inspect and Repair Vacuum Leaks

• Visually inspect all vacuum hoses and intake connections for cracks or disconnections.
• Use a smoke machine or carburetor cleaner to identify leaks.
• Replace any damaged hoses and reassemble connections securely.

3. Clean or Replace MAF Sensor

• Disconnect the MAF sensor electrical connector.
• Remove the MAF sensor from the air intake tube using a Torx screwdriver.
• Clean the MAF sensor using MAF cleaner or replace it if damaged.
• Reinstall the MAF sensor and reconnect the electrical connector.

4. Check Fuel System

• Connect a fuel pressure gauge to the fuel rail.
• Turn the ignition to the "ON" position without starting the engine to check fuel pressure (should meet manufacturer specifications).
• If pressure is low, inspect the fuel pump and replace the fuel filter if necessary.

5. Inspect Throttle Body and Intake Manifold

• Remove the air intake duct to access the throttle body.
• Clean the throttle body using throttle body cleaner and a soft cloth to remove carbon buildup.
• Reassemble the intake duct and ensure all connections are tight.