why does my Toyota Highlander Third Generation (2014-2019) feel like it's misfiring?

Solution

1. Preparation

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

2. Replace Spark Plugs

• Remove the engine cover if equipped.
• Using a socket wrench, remove the spark plug wires or ignition coils.
• Unscrew and remove the old spark plugs using a spark plug socket.
• Inspect the spark plug holes for debris and clean if necessary.
• Install new spark plugs, ensuring they are gapped to the manufacturer’s specifications (typically around 0.043 inches for this model).
• Reattach ignition coils or spark plug wires securely.

3. Inspect and Replace Ignition Coils (if necessary)

• If misfire codes indicate a specific cylinder, remove the corresponding ignition coil.
• Test the ignition coil with a multimeter; compare readings to manufacturer specifications.
• If faulty, replace the ignition coil with a new one.
• Reinstall the ignition coil and ensure it is seated properly.

4. Check Fuel Injectors

• If fuel delivery issues are suspected, remove the fuel injectors for inspection.
• Clean fuel injectors using a professional cleaning kit or replace if clogged or damaged.
• Reinstall the injectors, ensuring they are seated correctly with new O-rings.

5. Inspect Air Intake System

• Check the air filter and replace if clogged or dirty.
• Inspect hoses and connections for vacuum leaks; replace any damaged hoses.
• Ensure the throttle body is clean and free from carbon buildup.