how to fix P0174 lean code in my Tesla Outback 5th Generation (2015-2019)

Solution

1. Preparation

• Gather tools and parts: OBD-II scanner, fuel pressure gauge, multimeter, socket set, MAF cleaner, vacuum gauge.
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Inspect and Repair Vacuum Leaks

• Use a vacuum gauge to check for leaks:
  • Connect the vacuum gauge to a vacuum port on the intake manifold.
  • A reading below 18 inHg indicates a possible leak.
• Visually inspect all vacuum lines for cracks or disconnections. Replace any damaged hoses.

3. Clean or Replace the MAF Sensor

• Locate the MAF sensor in the intake system.
• Disconnect the electrical connector and remove the sensor.
• Use MAF cleaner to spray the sensing elements; allow to dry completely.
• Reinstall the sensor and reconnect the electrical connector.

4. Check Fuel Pressure

• Connect the fuel pressure gauge to the fuel rail's service port.
• Turn the ignition to the "ON" position (do not start) to check pressure:
  • Ensure the reading matches the manufacturer’s specifications (typically 40-55 psi).
• If pressure is low, inspect the fuel pump and filter for issues.

5. Inspect Fuel Injectors

• Check injectors for clogs using a multimeter to test resistance:
  • Values should typically be between 12-16 ohms.
• If any injectors are faulty, replace them.