how to fix P0171 code on Toyota Camry Eighth Generation (2018-present)

Solution

1. Preparation

• Tools Required: OBD-II scanner, fuel pressure gauge, multimeter, socket set, vacuum gauge, cleaning supplies.
• Disconnect the negative battery terminal to ensure safety during repairs.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Visually inspect and feel around the intake manifold, vacuum hoses, and throttle body for signs of leaks.
  2. If any leaks are found, replace the faulty components (e.g., gaskets, hoses).
  3. Clean the throttle body using throttle body cleaner to ensure optimal airflow.

3. Test and Replace Fuel System Components

• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail and turn the ignition to the "ON" position without starting the engine to check fuel pressure.
  2. Compare the reading with the manufacturer specifications (typically around 35-50 psi for most models).
  3. If fuel pressure is low, inspect the fuel pump and filter. Replace any faulty components.
  4. If fuel pressure is adequate, proceed to inspect fuel injectors: remove, clean or replace as necessary.

4. Clean or Replace MAF Sensor

• Sub-steps:
  1. Disconnect the MAF sensor electrical connector.
  2. Remove the MAF sensor from the air intake assembly using the socket set.
  3. Clean the sensor with MAF sensor cleaner and let it dry completely before reinstalling.
  4. If cleaning does not resolve the issue, replace the MAF sensor.

5. Inspect Oxygen Sensors

• Sub-steps:
  1. Check the upstream oxygen sensor wiring and connector for any damage.
  2. Test the oxygen sensor using a multimeter to verify it is operating within specifications (voltage output).
  3. Replace the oxygen sensor if it is faulty.