how to fix P0174 code in Toyota Tacoma N300 (2016-Present)

Solution

1. Preparation

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

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses for cracks, wear, or disconnections.
  2. Use a smoke machine or carburetor cleaner to identify leaks while the engine is running.
  3. Replace any damaged hoses or components as necessary.

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Unplug the MAF sensor electrical connector.
  2. Remove the MAF sensor using a Torx or screwdriver.
  3. Clean the sensor with MAF cleaner spray; do not touch the sensor element.
  4. If damaged, replace the MAF sensor with a new one and reconnect the electrical connector.

4. Check Fuel System

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail test port.
  2. Turn the ignition to the "ON" position to check the fuel pressure; compare the reading to the manufacturer’s specification (typically around 50-60 psi).
  3. If low, check the fuel filter and fuel pump for proper operation.
  4. Inspect fuel injectors; consider testing their resistance and spray pattern.

5. Inspect Exhaust System

• Sub-steps:
  1. Visually inspect the exhaust system for cracks or holes, especially near the manifold and O2 sensors.
  2. Repair or replace any damaged exhaust components.

6. Verify ECT Sensor Functionality

• Sub-steps:
  1. Unplug the ECT sensor connector.
  2. Use a multimeter to check the resistance of the ECT sensor at various temperatures (refer to service manual specs).
  3. Replace the ECT sensor if it’s out of specification.