how to diagnose P0301 misfire code on Honda Civic 10th Generation (2016-2021)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, fuel injector cleaner
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool before working on it.

2. Replace Ignition Coil and Spark Plug (if necessary)

1. Remove the engine cover (if applicable) using a socket set.
2. Locate the ignition coil for cylinder 1.
3. Disconnect the electrical connector from the ignition coil.
4. Remove the bolt securing the ignition coil using the socket set.
5. Pull out the ignition coil from the spark plug tube.
6. If the spark plug appears worn or damaged, remove it using a spark plug socket.
7. Install the new spark plug, tightening to manufacturer specifications (typically 13-16 ft-lbs).
8. Reinstall the ignition coil, securing it with the bolt and reconnecting the electrical connector.

3. Test Fuel Injector (if necessary)

1. Using a multimeter, check the resistance of the fuel injector for cylinder 1 according to specifications (usually 12-16 ohms).
2. If out of spec, replace the fuel injector with a new one.
3. If cleaning is needed, apply fuel injector cleaner directly into the fuel rail or use a fuel injector cleaning kit.

4. Reassemble and Connect Battery

1. Reinstall any components that were removed, including the engine cover.
2. Reconnect the negative battery terminal.
3. Ensure all tools are removed from the engine bay.