how to fix P0174 code in Toyota Corolla E170 (2013-2019)

Learn how to diagnose and fix P0174 engine too lean condition in Toyota Corolla E170. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect vacuum hoses and connections.
  2. Use a smoke machine or carburetor cleaner to identify any leaks.
  3. Replace damaged hoses or gaskets as necessary.
• Tools Required: Smoke machine or carburetor cleaner, pliers, and replacement hoses/gaskets.

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor on the air intake tube.
  2. Disconnect the electrical connector.
  3. Remove the sensor using a Torx or Phillips screwdriver.
  4. Clean the sensor with MAF cleaner or replace it if damaged.
  5. Reinstall the sensor and reconnect the electrical connector.
• Tools Required: Torx or Phillips screwdriver, MAF cleaner.

4. Check Fuel Pressure

• Sub-steps:
  1. Locate the fuel pressure test port on the fuel rail.
  2. Use a fuel pressure gauge to test the fuel pressure.
  3. If the pressure is low, check the fuel pump and filter.
  4. Replace the fuel pump or filter as necessary.
• Tools Required: Fuel pressure gauge, basic socket set.

5. Clean Fuel Injectors

• Sub-steps:
  1. Remove the fuel rail to access the injectors.
  2. Clean the injectors using injector cleaner or replace them if faulty.
  3. Reinstall the fuel rail and ensure all connections are secure.
• Tools Required: Basic socket set, injector cleaner.