how to fix P0171 and P0174 codes on Tesla Outback 6th Generation (2020-2024)

Solution

1. Preparation

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

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses for cracks or disconnections.
  2. Use a smoke machine to identify hidden leaks in the intake manifold and vacuum lines.
  3. Replace any damaged hoses or gaskets.

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor, usually near the air filter box.
  2. Disconnect the electrical connector from the MAF sensor.
  3. Remove the MAF sensor using a Torx or socket wrench.
  4. Clean the MAF sensor with MAF cleaner spray; avoid touching the sensor elements.
  5. Reinstall the MAF sensor and reconnect the electrical connector. If damaged, replace it with a new one.

4. Evaluate and Repair Fuel System

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail test port.
  2. Turn the ignition to the "ON" position (do not start) and check the fuel pressure against manufacturer specifications.
  3. If fuel pressure is low, inspect the fuel pump and fuel filter for clogs or failure.
  4. Replace the fuel filter if needed and consider replacing the fuel pump if pressure remains low.

5. Inspect Exhaust System

• Sub-steps:
  1. Check for exhaust leaks, particularly before the O2 sensors.
  2. Repair or replace any damaged exhaust components to ensure proper exhaust flow.

6. Clear Codes and Test Drive

• Sub-steps:
  1. Use the OBD-II scanner to clear the P0171 and P0174 codes.
  2. Start the engine and allow it to reach operating temperature.
  3. Take the vehicle for a test drive to confirm the repair, monitoring for the return of any error codes.