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

Solution

1. Preparation

• Gather all tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  • Visually inspect vacuum hoses for cracks or disconnections.
  • Use a smoke machine to identify hard-to-find leaks.
  • Replace any damaged hoses or gaskets identified during inspection.

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Remove the MAF sensor from the air intake.
  • Spray MAF cleaner on the sensor element, avoiding touching it directly.
  • Allow it to dry completely before reinstalling.
  • If cleaning doesn’t resolve the issue, replace the MAF sensor with a new one.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail.
  • Turn the ignition to the "ON" position without starting the engine to check for pressure.
  • If pressure is below specifications, inspect and replace the fuel pump or fuel filter as necessary.

5. Inspect and Clean Fuel Injectors

• Sub-steps:
  • Remove fuel injectors from the engine.
  • Use a fuel injector cleaner kit or ultrasonic cleaner to clean the injectors.
  • Test the injectors' resistance with a multimeter; if out of spec, replace them.

6. Replace Oxygen Sensor (if necessary)

• Sub-steps:
  • Disconnect the oxygen sensor wiring harness.
  • Use an O2 sensor socket to remove the sensor.
  • Install the new oxygen sensor and reconnect the wiring harness.