what does it mean when my Tesla Outback shows a P0171 code?

Solution

1. Preparation

• Tools Needed: OBD-II scanner, socket set, fuel pressure gauge, multimeter, vacuum gauge, cleaning supplies for MAF sensor.
• Disconnect the battery to ensure safety during repairs.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Visually inspect all hoses and connections in the air intake system.
  2. Tighten any loose clamps and replace any damaged hoses.
  3. If leaks are found, replace the affected components.

3. Check and Clean MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the air intake manifold.
  2. Remove the electrical connector and unscrew the sensor from the housing.
  3. Clean the sensor with MAF cleaner and allow it to dry completely before reinstalling.
  4. Reattach the MAF sensor and connector.

4. Test Fuel Pressure

• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail test port.
  2. Start the engine and check the fuel pressure reading; compare it with manufacturer specifications.
  3. If the pressure is low, inspect the fuel pump and fuel filter for issues and replace if necessary.

5. Inspect Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors in the exhaust system.
  2. Use a multimeter to test the voltage output of the sensors to ensure they are functioning correctly.
  3. Replace any sensors that are outside of manufacturer specifications.