how to fix the P0171 code on my BMW 5 Series G30/G31 (2017-2024)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool before starting work.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum pump, hose clamps, and a flashlight.
  • Use a vacuum pump to test hoses and gaskets for leaks.
  • Inspect the intake manifold and throttle body for signs of damage or wear.
  • Replace any damaged hoses or gaskets found during inspection.

3. Fuel Pressure Check

• Tools Required: Fuel pressure gauge.
  • Locate the fuel rail and connect the fuel pressure gauge to the service port.
  • Turn the ignition to the "ON" position (do not start the engine) to check fuel pressure.
  • If pressure is below specifications, check the fuel pump and filter; replace if necessary.

4. Clean MAF Sensor

• Tools Required: MAF sensor cleaner.
  • Disconnect the MAF sensor connector.
  • Remove the MAF sensor from the intake.
  • Spray the MAF sensor with MAF cleaner and allow it to dry completely before reinstalling.

5. Replace Oxygen Sensors (if faulty)

• Tools Required: O2 sensor socket, wrench.
  • Identify the upstream oxygen sensor(s) using the service manual.
  • Disconnect the electrical connector and unscrew the sensor.
  • Install the new oxygen sensor and reconnect the electrical connector, ensuring it is secured.

6. Reassemble and Clear Codes

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0171 code.
• Start the engine and allow it to reach operating temperature.