my Toyota Highlander Third Generation (2014-2019) has a rough idle when I first start it

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a level surface with the engine off and allow it to cool down.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Spark Plugs

• Remove the engine cover if necessary.
• Disconnect the ignition coil connectors.
• Remove the ignition coils using a socket set.
• Use a spark plug socket to remove the spark plugs.
• Inspect the spark plugs for wear and replace them if necessary.
• Install new spark plugs to the manufacturer’s torque specifications (typically 13-15 ft-lbs).
• Reinstall the ignition coils and reconnect the connectors.

3. Clean the Throttle Body

• Remove the air intake duct to gain access to the throttle body.
• Use throttle body cleaner and a soft brush to clean the throttle plate and surrounding areas.
• Wipe down the throttle body with a clean rag.
• Reinstall the air intake duct securely.

4. Check and Replace Fuel Filter (if applicable)

• Locate the fuel filter and inspect for leaks.
• Use a wrench to disconnect the fuel lines (be cautious of fuel spillage).
• Remove the fuel filter and replace it with a new one.
• Reconnect the fuel lines securely.

5. Reconnect Battery and Start Engine

• Reconnect the battery terminals (positive first, then negative).
• Start the engine and allow it to idle, observing for any irregularities.