how to fix a misfire in my Toyota Highlander XU70 (2020-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to avoid electrical shorts.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Fuel pressure gauge
• Multimeter

2. Replace Spark Plugs

1. Remove the engine cover if applicable.
2. Using the socket set, carefully remove the spark plug wires or coils.
3. Extract the old spark plugs using a spark plug socket.
4. Inspect the spark plugs for wear and replace with new ones as needed.
5. Torque the new spark plugs to the manufacturer-recommended specifications (usually around 13-15 lb-ft).

3. Inspect and Replace Ignition Coils

1. If misfire codes indicate specific cylinders, remove the ignition coils from those cylinders.
2. Test each ignition coil with a multimeter to ensure they are functioning within specifications.
3. Replace any faulty ignition coils with new ones.
4. Reinstall the ignition coils, ensuring they are seated properly.

4. Check and Clean Fuel Injectors

1. If fuel injector issues are suspected, remove the fuel rail to access the injectors.
2. Inspect the injectors for clogs and clean them using an appropriate fuel injector cleaner or replace if necessary.
3. Reinstall the fuel rail and ensure proper seating and sealing.

5. Verify Fuel Delivery

1. Connect the fuel pressure gauge to the fuel rail.
2. Turn the ignition to the "ON" position (without starting the engine) and check pressure readings.
3. Ensure the pressure is within the specified range for the vehicle (consult service manual).
4. Replace the fuel filter if pressure is low.