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

Solution

1. Preparation

• Gather necessary tools and replacement parts.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
  2. Use a smoke machine or carburetor cleaner to identify leaks around the manifold and hoses.
  3. Replace any damaged hoses and tighten all connections.

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 from the duct.
  3. Clean the MAF sensor carefully with MAF cleaner spray; avoid touching the sensor element.
  4. Allow it to dry completely before reinstalling.
  5. If cleaning does not resolve the issue, replace with a new MAF sensor.

4. Check Fuel System

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail's test port.
  2. Turn the ignition to the ON position (do not start the engine) to check for fuel pressure.
  3. Compare the reading with manufacturer's specifications (typically 50-60 psi for Tacoma).
  4. If pressure is low, check the fuel pump and filter for proper operation and replace if necessary.

5. Inspect Fuel Injectors

• Sub-steps:
  1. Remove the fuel rail with injectors attached (ensure fuel pressure is relieved first).
  2. Inspect injectors for clogs using a multimeter or by performing a resistance test.
  3. Clean injectors using an ultrasonic cleaner or replace them if they are faulty.

6. Recheck and Clear Codes

• Sub-steps:
  1. Reconnect all components and battery terminal.
  2. Start the engine and let it reach operating temperature.
  3. Use the OBD-II scanner to clear the P0171 code.
  4. Monitor the system for any reoccurrence of the code.