how to fix P0171 lean code in Toyota RAV4 XA40 (2013-2018)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before starting the work.

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Visually inspect the intake hoses for cracks or disconnections.
  • Tighten any loose clamps or replace damaged hoses.
  • If vacuum leaks are found, replace affected hoses or components.
• Tools Required: Screwdriver, pliers.

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Locate the MAF sensor in the air intake duct.
  • Disconnect the electrical connector and remove the sensor.
  • Clean the MAF sensor using MAF cleaner spray; allow it to dry.
  • If cleaning does not resolve the issue, replace the MAF sensor with a new one.
• Tools Required: Torx or Phillips screwdriver, MAF cleaner spray.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail's service port.
  • Turn the ignition to the ON position (do not start the engine) to check pressure; it should match manufacturer's specifications.
  • If pressure is low, inspect the fuel pump and fuel filter, replacing them as necessary.
• Tools Required: Fuel pressure gauge, basic hand tools.

5. Inspect Fuel Injectors

• Sub-steps:
  • Remove the engine cover if necessary to access fuel injectors.
  • Inspect for any fuel leaks around the injectors.
  • Perform a balance test or use a fuel injector cleaner if clogs are suspected.
• Tools Required: Basic hand tools, fuel injector cleaner.