how to fix P0171 lean code in Toyota Tacoma N300 (2016-Present)

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the battery to prevent electrical shorts.
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Inspect and Repair Air Intake System

• Sub-steps:

  1. Remove the engine cover if necessary to access the air intake system.
  2. Visually inspect all hoses and connections for cracks, breaks, or loose clamps.
  3. Replace any damaged hoses or re-tighten loose clamps.
  4. Clean the air filter and replace it if it’s too dirty.

• Tools Required:

  • Socket set
  • Screwdrivers

3. Clean or Replace MAF Sensor

• Sub-steps:

  1. Disconnect the electrical connector from the MAF sensor.
  2. Remove the MAF sensor from the air intake duct.
  3. Spray MAF cleaner onto the sensor elements and let it dry.
  4. Reinstall the MAF sensor and reconnect the electrical connector.

• Tools Required:

  • MAF cleaner
  • Torx or socket set

4. Check Fuel System

• Sub-steps:

  1. Connect a fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the ON position (do not start) and check the fuel pressure reading.
  3. If the reading is below specifications (typically around 50-60 PSI for Tacoma), inspect the fuel pump and replace if necessary.
  4. Replace the fuel filter if it has not been changed according to maintenance schedule.

• Tools Required:

  • Fuel pressure gauge
  • Socket set

5. Inspect and Replace Oxygen Sensors (if necessary)

• Sub-steps:

  1. Access the oxygen sensors located on the exhaust system.
  2. Use an oxygen sensor socket to remove the sensors.
  3. Install new sensors and torque to manufacturer specifications (typically around 30-40 ft-lbs).

• Tools Required:

  • Oxygen sensor socket
  • Torque wrench