how to fix P0174 code in Toyota Highlander Fourth Generation (2020-present)

Solution

1. Preparation

• Gather tools and parts required: OBD-II scanner, socket set, torque wrench, vacuum gauge, fuel pressure gauge, cleaner for MAF sensor, and any necessary replacement parts (hoses, gaskets, etc.).
• Disconnect the vehicle battery to prevent any electrical shorts during repairs.

2. Inspect and Repair Air Intake System

• Sub-step 1: Check and replace any damaged or disconnected vacuum lines.
  • Use a vacuum gauge to identify any leaks.
• Sub-step 2: Inspect the air intake hoses for cracks or wear and replace as necessary.
• Sub-step 3: Clean the MAF sensor using a dedicated MAF cleaner.
  • Allow the sensor to dry completely before reinstallation.

3. Test and Repair Fuel System

• Sub-step 1: Use a fuel pressure gauge to check fuel pressure against manufacturer specifications.
  • If pressure is low, it may indicate a failing fuel pump or clogged fuel filter.
• Sub-step 2: Inspect and clean the fuel injectors if they are clogged.
  • Use an ultrasonic cleaner if necessary, or replace injectors if cleaning does not resolve the issue.

4. Reassemble and Reconnect

• Sub-step 1: Reconnect all components that were removed or inspected in the previous steps.
• Sub-step 2: Reconnect the vehicle battery.