how to fix P0174 system too lean bank 2 in Toyota Highlander Fourth Generation (2020-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical systems.
• Allow the engine to cool completely before beginning work.

2. Inspect and Repair Air Intake System

• Tools Required: Socket set, screwdrivers
• Visually inspect the air intake system for any signs of leaks or damage.
• Tighten any loose clamps or connections.
• Replace any damaged hoses or components as necessary.

3. Check and Clean MAF Sensor

• Tools Required: MAF cleaner, soft cloth
• Locate the MAF sensor in the air intake duct.
• Disconnect the electrical connector and remove the sensor.
• Use MAF cleaner to spray the sensor elements and allow it to dry completely before reinstalling.

4. Fuel Pressure Test and Repair

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail.
• Start the engine and observe the fuel pressure reading; it should match factory specifications (typically 50-60 PSI).
• If pressure is low, check the fuel pump and filter for issues or replace as necessary.

5. Inspect and Repair Vacuum Lines

• Tools Required: Visual inspection tools
• Follow vacuum lines from the intake manifold to the various components.
• Look for cracks, wear, or disconnections, and replace any damaged lines.

6. Test and Replace Fuel Injectors (if necessary)

• Tools Required: Injector cleaner, multimeter
• Use a multimeter to test the resistance of each injector.
• If any injectors are out of specification, remove and replace them.
• Clean the remaining injectors using an injector cleaning kit if needed.