how to fix the P0171 code on my BMW 3 Series G20/G21 (2019-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety during repairs.

2. Inspect and Repair Air Intake System

• Tools Required: Screwdrivers, pliers, flashlight
• Visually inspect the air intake hoses and connections for cracks or loose fittings.
• If any damage is found, replace the damaged hoses or tighten loose connections.

3. Clean or Replace MAF Sensor

• Tools Required: MAF cleaner, torx screwdriver
• Remove the MAF sensor from the air intake system by unscrewing it.
• Clean the MAF sensor with MAF cleaner and let it dry completely.
• If the sensor is damaged or not functioning properly, replace it with a new one.

4. Check Fuel System

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail.
• Start the engine and check the fuel pressure. Refer to the manufacturer’s specifications for correct pressure values.
• If the pressure is low, inspect the fuel pump, fuel filter, and fuel injectors for proper operation and replace any faulty components.

5. Inspect Vacuum Lines

• Tools Required: Visual inspection tools
• Check all vacuum hoses connected to the intake manifold for cracks or disconnections.
• Replace any damaged vacuum lines to ensure proper vacuum levels.

6. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0171 code.