how to fix P0303 misfire code on Honda Accord 9th Generation (2013-2017)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery negative terminal to ensure safety during repairs.
• Allow the engine to cool before beginning work.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket
• Remove the ignition coil from cylinder 3 by unscrewing the bolts and disconnecting the electrical connector.
• Remove the spark plug using a spark plug socket and ratchet.
• Inspect and replace with a new spark plug that meets OEM specifications (typically NGK or Denso).
• Torque the new spark plug to the manufacturer’s specification (usually around 13-15 lb-ft).
• Reattach the ignition coil.

3. Test and Replace Ignition Coil (if necessary)

• Tools Required: Multimeter
• Use a multimeter to test the ignition coil for cylinder 3. Check primary and secondary resistance values as per the service manual.
• If the coil is faulty, replace it with a new one, ensuring it is compatible with the vehicle.
• Reinstall the ignition coil and reconnect the electrical connector.

4. Inspect and Clean Fuel Injector

• Tools Required: Fuel injector cleaner, small screwdriver
• Remove the fuel injector from cylinder 3 by detaching it from the fuel rail and electrical connector.
• Clean the fuel injector using a proper fuel injector cleaner.
• If the injector is faulty, replace it with a new one.
• Reinstall the injector and ensure all connections are secure.

5. Compression Test (if needed)

• Tools Required: Compression tester
• Remove the spark plug from cylinder 3.
• Install the compression tester and crank the engine several times.
• Record the compression reading. If it is below specifications, further investigation into the engine internals is required.