my BMW 3 Series G20/G21 (2019-2024) has a P0171 code what should I do

Solution

1. Preparation

1. Gather tools: OBD-II scanner, multimeter, socket set, torque wrench, vacuum gauge, and cleaning supplies.
2. Disconnect the vehicle's battery to ensure safety while working on electrical components.

2. Inspect and Repair Air Intake System

1. Visually inspect all air intake hoses for cracks or damage.
2. Tighten any loose clamps and replace any damaged hoses.
3. If necessary, replace the air filter if it is clogged.

3. Clean MAF Sensor

1. Remove the MAF sensor from the air intake duct.
2. Use MAF cleaner to spray the sensor gently, avoiding touching the sensor element.
3. Allow it to dry completely before reinstalling.

4. Check Fuel Delivery

1. Connect a fuel pressure gauge to the fuel rail to check the fuel pressure against manufacturer specifications.
2. If pressure is low, inspect fuel pump and filter for clogs or malfunctions.
3. Verify that fuel injectors are clean and functioning by performing a resistance test with a multimeter.

5. Inspect Vacuum Lines

1. Check all vacuum lines for cracks and leaks, especially around the intake manifold.
2. Replace any damaged vacuum hoses found during the inspection.

6. Reconnect Battery and Clear Codes

1. Reconnect the vehicle's battery.
2. Use the OBD-II scanner to clear the error codes from the system.