why is my Toyota Camry Eighth Generation (2018-present) engine light on with P0171 code

Solution

1. Preparation

• Tools Required: OBD-II scanner, vacuum gauge, fuel pressure gauge, MAF cleaner, multimeter, basic hand tools.
• Safety Warnings: Disconnect the battery before working on electrical systems; ensure the engine is cool before inspecting components.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Start the engine and listen for hissing sounds around hoses and intake manifold.
  2. Use a smoke machine or spray soapy water around suspected areas to identify leaks.
  3. Replace any damaged or cracked hoses or gaskets found during inspection.

3. Test and Clean MAF Sensor

• Sub-steps:
  1. Remove the MAF sensor from the air intake duct.
  2. Spray MAF cleaner on the sensing element and allow it to dry completely.
  3. Reinstall the MAF sensor ensuring proper seating and connections.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail.
  2. Start the engine and observe the pressure reading; it should match specifications.
  3. If the pressure is low, check the fuel pump and filter for issues and replace as necessary.

5. Inspect Fuel Injectors

• Sub-steps:
  1. Remove the fuel injectors from the rail.
  2. Clean injectors with a fuel injector cleaning kit or replace if they are clogged.
  3. Reinstall injectors ensuring proper sealing and connection.