how to fix P0171 lean code in BMW 5 Series F10/F11 (2010-2017)

Solution

1. Preparation

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

2. Inspect Air Intake System

• Tools Required: Hose clamp pliers, screwdriver, flashlight.
• Check all air intake hoses for cracks and secure connections. Replace any damaged hoses.
• Inspect the intake manifold gasket for leaks. Replace if necessary.

3. Test and Clean MAF Sensor

• Tools Required: MAF cleaner or electrical cleaner.
• Remove the MAF sensor from the air intake duct.
• Clean the sensor with appropriate cleaner, ensuring no residue is left behind. Allow it to dry completely before reinstalling.

4. Check Fuel Pressure

• Tools Required: Fuel pressure gauge.
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition to the ON position (do not start) and check the pressure reading against manufacturer specifications (typically around 50-60 psi for BMW).
• If pressure is low, check the fuel pump and filter for issues, replacing components as necessary.

5. Inspect and Clean Fuel Injectors

• Tools Required: Injector cleaning kit, socket set.
• Remove the fuel injectors from the engine.
• Use an injector cleaning kit to clean the injectors. If they are damaged or still clogged after cleaning, replace them.

6. Verify Oxygen Sensor Function

• Tools Required: OBD-II scanner, multimeter.
• Use the OBD-II scanner to monitor the live data from the oxygen sensors.
• If the sensors are not providing accurate readings, replace them as needed.