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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool before working on any components.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  • Visually inspect all vacuum lines connected to the intake manifold and associated systems.
  • Use a smoke machine or carburetor cleaner to identify leaks; apply cleaner around suspected areas and watch for RPM changes.
  • Replace any damaged or worn vacuum hoses.

3. Clean or Replace MAF Sensor

• Tools Required:
  • MAF sensor cleaner
  • Screwdriver set
• Sub-steps:
  • Locate the MAF sensor on the intake tube.
  • Disconnect the electrical connector and remove the sensor from the intake.
  • Clean the sensor using MAF cleaner; allow it to dry completely before reinstallation.
  • Reinstall the MAF sensor and reconnect the electrical connector.

4. Check and Repair Fuel System

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail and turn the ignition to the "ON" position (do not start the engine) to check the fuel pressure.
  • If the pressure is below specifications, inspect the fuel pump and filter for proper operation. Replace as needed.
  • Check fuel injectors for clogs or leaks and clean or replace them if necessary.

5. Inspect Intake Manifold Gasket

• Sub-steps:
  • Remove the intake manifold as per manufacturer specifications.
  • Inspect the gasket for any signs of wear or damage.
  • Replace the gasket if necessary and reassemble the intake manifold ensuring all bolts are properly torqued.