how to diagnose why my Honda Accord 10th Generation (2018-2022) has a rough idle

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is on a level surface and the engine is cool.
• Disconnect the negative battery terminal for safety.

2. Clean or Replace Air Filter

• Remove the air filter cover by unscrewing any fasteners.
• Take out the existing air filter and inspect it. If dirty, replace it with a new one.
• Reinstall the air filter and cover securely.

3. Fuel System Maintenance

• Use a fuel pressure gauge to connect to the fuel rail.
• Turn the ignition to the "ON" position without starting the engine to check for proper fuel pressure.
• If pressure is low, replace the fuel pump or filter as needed.

4. Spark Plug Inspection

• Remove the ignition coils by unscrewing them and disconnecting the electrical connectors.
• Take out the spark plugs using a spark plug socket and inspect for wear or deposits.
• Replace worn spark plugs with new ones, ensuring to torque them to the manufacturer’s specifications.

5. Vacuum Leak Check

• Inspect all vacuum hoses visually and by touch for cracks or disconnections.
• Replace any damaged hoses.
• If no issues are found, perform a smoke test to identify hidden leaks.

6. Throttle Body Cleaning

• Remove the throttle body intake duct by loosening the clamps and disconnecting the sensors.
• Clean the throttle body using throttle body cleaner and a soft cloth, focusing on the throttle plate and surrounding areas.
• Reinstall the throttle body and intake duct securely.

7. Oil Change (if necessary)

• If the oil is low or dirty, drain the old oil using an oil drain pan.
• Replace the oil filter and refill with the correct type and quantity of engine oil as specified in the owner's manual.