how to fix P0303 misfire in Honda Accord 9th Generation (2013-2017)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a flat surface and the ignition is off.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coil from cylinder 3 by unbolting it and disconnecting the electrical connector.
• Using a spark plug socket, carefully unscrew and remove the old spark plug.
• Inspect the new spark plug's gap and ensure it is set to the manufacturer's specifications (usually around 0.044 inches for Honda).
• Install the new spark plug by threading it in by hand, then torque it to the manufacturer’s specification (typically 13 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Replace Ignition Coil (if necessary)

• Tools Required: Socket set, torque wrench.
• If the ignition coil was found defective during diagnostics, remove the coil from cylinder 3.
• Install the new ignition coil by securing it in place and connecting the electrical connector.
• Ensure that all connections are secure and that the coil is seated properly.

4. Check Fuel Injector (if necessary)

• Tools Required: Fuel injector cleaning kit or replacement injector.
• Remove the fuel rail if the injector needs replacing.
• Disconnect the fuel line (be cautious of fuel spills and wear safety goggles).
• Remove the faulty fuel injector and replace it with a new one.
• Reassemble the fuel rail, ensuring all seals are seated properly.