how to fix P0171 code on my Toyota Tacoma N300 (2016-Present)

Solution

1. Preparation

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

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Visually inspect all vacuum hoses and the intake manifold for cracks or disconnections.
  2. Replace any damaged hoses or reattach loose connections.
• Tools Required: Screwdrivers, pliers.

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the air intake duct.
  2. Disconnect the electrical connector and remove the sensor.
  3. Use MAF sensor cleaner to spray and clean the sensor.
  4. Allow it to dry completely, then reinstall the sensor.
• Tools Required: MAF sensor cleaner, Torx or Phillips screwdriver.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail test port.
  2. Turn the ignition key to the ON position (do not start the engine) to build pressure.
  3. Compare the gauge reading to manufacturer specifications (typically around 50-60 psi for Tacoma).
  4. If pressure is low, inspect the fuel pump and filter for potential issues and replace as necessary.
• Tools Required: Fuel pressure gauge.

5. Inspect Fuel Injectors

• Sub-steps:
  1. Remove the fuel rail to access the injectors.
  2. Visually inspect injectors for clogs or leaks.
  3. Clean or replace any faulty injectors as necessary.
• Tools Required: Socket set, injector cleaner.

6. Replace Oxygen Sensors (if necessary)

• Sub-steps:
  1. Locate the upstream oxygen sensor (usually before the catalytic converter).
  2. Disconnect the electrical connector and use a wrench to remove the sensor.
  3. Install the new oxygen sensor, ensuring it is tightened to the manufacturer’s torque specifications (typically around 30 lb-ft).
• Tools Required: Oxygen sensor socket, wrench.