how to fix P0171/ P0174 lean code on my BMW X5 F15 (2014-2019)

Solution

1. Preparation

• Gather tools and materials.
• Disconnect the battery to ensure safety while working on electrical components.
• Tools required: OBD-II scanner, socket set, multimeter, vacuum gauge, MAF cleaner, and basic hand tools.

2. Inspect and Repair Air Intake System

• Sub-step 1: Remove the engine cover and air intake duct.
• Sub-step 2: Visually inspect the air filter for clogging and replace if necessary.
• Sub-step 3: Check for any cracks or loose connections in the intake manifold and air ducts; repair or replace as needed.

3. Clean or Replace MAF Sensor

• Sub-step 1: Disconnect the MAF sensor electrical connector.
• Sub-step 2: Remove the MAF sensor from the air intake duct.
• Sub-step 3: Use MAF sensor cleaner to clean the sensor element; allow it to dry completely before reinstallation.
• Sub-step 4: Reinstall the MAF sensor and reconnect the electrical connector.

4. Check Fuel System

• Sub-step 1: Connect a fuel pressure gauge to the fuel rail.
• Sub-step 2: Turn the ignition to the "ON" position without starting the engine; check the fuel pressure reading against manufacturer specifications.
• Sub-step 3: If pressure is low, inspect and replace the fuel pump or fuel filter as necessary.

5. Inspect Fuel Injectors

• Sub-step 1: Remove the fuel rail with injectors attached.
• Sub-step 2: Perform a flow test on each injector to ensure they are functioning properly.
• Sub-step 3: Clean or replace any faulty injectors as needed.