how to fix P0303 misfire code on Honda Accord Eleventh Generation (2023-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Ensure the engine is cool before starting work.

2. Replace Spark Plug for Cylinder 3

• Tools Required: Spark plug socket, ratchet, torque wrench, anti-seize compound.
• Remove the engine cover if applicable.
• Locate and remove the spark plug wire or ignition coil for cylinder 3.
• Use a spark plug socket to remove the old spark plug.
• Inspect the old spark plug for wear; if necessary, clean the area around the spark plug hole.
• Install the new spark plug, applying anti-seize compound to the threads.
• Tighten the spark plug to the manufacturer's specified torque (typically 13-15 lb-ft).
• Reattach the ignition coil or spark plug wire.

3. Inspect and Replace Ignition Coil

• Tools Required: Socket set, torque wrench.
• Remove the ignition coil for cylinder 3 by unbolting it from the engine.
• Inspect the ignition coil for cracks or damage.
• Install a new ignition coil, ensuring it is seated properly.
• Bolt the ignition coil down to the specified torque (check service manual for exact value).

4. Check and Replace Fuel Injector (if necessary)

• Tools Required: Fuel injector removal tool, socket set.
• Disconnect the fuel injector connector for cylinder 3.
• Carefully remove the fuel rail (if required) to access the injector.
• Remove the old fuel injector and install the new one, ensuring O-rings are lubricated and seated correctly.
• Reassemble the fuel rail and reconnect all electrical connectors.