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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, feeler gauge, compression tester, multimeter, basic hand tools
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to prevent electrical shock.

2. Replace Spark Plug

1. Remove the engine cover (if applicable) using a socket set.
2. Disconnect the ignition coil connector and remove the ignition coil from cylinder 3.
3. Use a spark plug socket to remove the spark plug from cylinder 3.
4. Inspect the old spark plug for wear; if it is fouled or worn down, replace it with a new one, ensuring the gap is set to manufacturer specifications (typically around 0.043 inches).
5. Install the new spark plug and torque it to the manufacturer’s specification (usually about 13-16 lb-ft).
6. Reinstall the ignition coil and reconnect the electrical connector.

3. Replace Ignition Coil (if necessary)

1. If the ignition coil appears damaged or malfunctioning after inspection, remove the old coil from cylinder 3.
2. Install the new ignition coil, ensuring it is seated properly and connected securely.
3. Reinstall any components removed during the process.

4. Inspect and Clean Fuel Injector (if necessary)

1. Disconnect the fuel injector connector and remove the injector from cylinder 3.
2. Check the injector for clogs; if dirty, clean it using an appropriate fuel injector cleaner or replace it with a new injector.
3. Reinstall the fuel injector and reconnect the electrical connector.