my Toyota Highlander Fourth Generation (2020-present) has a rough idle when in drive what's the issu...

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety.
• Allow the engine to cool completely.

2. Clean or Replace Air Intake Components

• Tools Required: Screwdriver set, throttle body cleaner, rags.
• Remove the air intake duct and inspect for debris.
• Use throttle body cleaner and a rag to clean the throttle body, ensuring no residue remains.

3. Inspect and Replace Spark Plugs

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Remove the ignition coils by unscrewing and gently pulling them out.
• Use a spark plug socket to remove the spark plugs.
• Inspect spark plugs for wear; replace with OEM parts if necessary.
• Torque new spark plugs to the manufacturer’s specifications (usually around 13-16 lb-ft).

4. Check and Clean Fuel Injectors

• Tools Required: Fuel injector cleaning kit.
• Disconnect the fuel lines and remove the fuel injectors from the engine.
• Use a fuel injector cleaning kit to clean and test each injector.
• Reinstall injectors with new O-rings to prevent leaks.

5. Reassemble and Test

• Reconnect all components in reverse order of removal.
• Reconnect the battery and clear any error codes with the OBD-II scanner.
• Start the engine and allow it to idle; monitor for any irregularities.