my Honda Accord has a rough idle when stopped at a red light what’s wrong

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Ensure the vehicle is parked on a level surface.

2. Inspect and Replace Spark Plugs

• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Use a socket set to remove the spark plug wires or ignition coils.
  3. Use a spark plug socket to carefully remove each spark plug from the cylinder head.
  4. Inspect the old spark plugs for signs of wear, fouling, or improper gap.
  5. Install new spark plugs with the correct gap settings as per manufacturer specifications (typically around 0.044 inches).
  6. Reattach the ignition coils or spark plug wires.

3. Clean the Throttle Body

• Sub-steps:
  1. Locate the throttle body and remove the intake duct connected to it.
  2. Use throttle body cleaner and a soft brush or cloth to clean the inside of the throttle body.
  3. Ensure the throttle plate is free to move and not sticking.
  4. Reconnect the intake duct securely to the throttle body.

4. Check and Replace the Air Filter

• Sub-steps:
  1. Locate the air filter housing and remove the clips or screws.
  2. Take out the old air filter and inspect it for dirt and blockages.
  3. Install a new air filter that meets OEM specifications.
  4. Reassemble the air filter housing.

5. Test Fuel System Pressure

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "ON" position without starting the engine to check the fuel pressure reading.
  3. Compare the reading with the manufacturer's specifications (typically around 40-50 PSI).
  4. If pressure is low, inspect the fuel pump and fuel filter for possible replacement.