why does my Honda Civic 9th Generation (2012-2015) have a check engine light and code P0301

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the engine cover if necessary.
• Disconnect the ignition coil connector and remove the ignition coil.
• Remove the spark plug using a spark plug socket.
• Inspect the spark plug for wear or carbon buildup; replace if necessary.
• Install the new spark plug and torque to specification (typically around 13-16 lb-ft).
• Reinstall the ignition coil and reconnect the connector.

3. Inspect and Replace Ignition Coil (if needed)

• If the spark plug is in good condition, test or replace the ignition coil for cylinder 1.
• Tools Required: Socket set, multimeter.
• Remove the ignition coil for cylinder 1.
• Test the coil's resistance with a multimeter according to manufacturer specifications.
• If faulty, install a new ignition coil, ensuring proper alignment and connection.

4. Check Fuel Injector

• Test the fuel injector for cylinder 1 using a noid light to ensure it is receiving the correct pulse.
• If the injector is faulty, remove it from the fuel rail.
• Replace with a new injector and reconnect the fuel line and electrical connector.

5. Compression Test (if misfire persists)

• Tools Required: Compression tester.
• Remove spark plugs for all cylinders.
• Insert the compression tester into cylinder 1 and crank the engine.
• Compare the readings to manufacturer specifications; replace any faulty components if compression is low.