how to fix the P0303 misfire code on my Honda Civic 11th Generation (2022-Present)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal for safety.

2. Replace Spark Plug

• Remove the engine cover if necessary.
• Unplug the ignition coil connector for cylinder 3.
• Remove the ignition coil bolts and take out the ignition coil.
• Use a spark plug socket to carefully remove the spark plug.
• Inspect the old spark plug; if damaged or worn, install a new spark plug with the correct gap (typically around 0.044 inches for Honda).
• Replace the spark plug and torque it to the manufacturer’s specification (usually around 13 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Replace Ignition Coil (if necessary)

• If the ignition coil is found to be faulty, remove the coil as described above.
• Install a new ignition coil specific to the 2022 Honda Civic.
• Secure it in place with the bolts and reconnect the electrical connector.

4. Clean or Replace Fuel Injector (if necessary)

• If the fuel injector is clogged, remove it according to your repair manual.
• Clean the injector using a specialized injector cleaning kit or replace it with a new injector.
• Reinstall the fuel injector and ensure it is seated correctly.

5. Perform Compression Test (if necessary)

• If compression is low, remove the spark plug and screw in a compression tester into cylinder 3.
• Crank the engine and record the reading. Compare it to the manufacturer’s specifications.
• If compression is low, further investigation into engine internals may be required.