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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench
• Remove the engine cover if necessary.
• Disconnect the ignition coil connector on cylinder 1.
• Remove the ignition coil using a socket.
• Unscrew and remove the spark plug from cylinder 1 using the spark plug socket.
• Inspect the old spark plug and ensure the new spark plug is gapped according to manufacturer specifications.
• Install the new spark plug and torque to the specified value (typically around 13-16 lb-ft).

3. Inspect and Replace Ignition Coil

• Reinstall the ignition coil to cylinder 1 and reconnect the wiring harness.
• If the ignition coil appears damaged or if the misfire persists after replacing the spark plug, replace the ignition coil with a new one.

4. Check Fuel Injector

• Tools Required: Fuel injector cleaner, basic hand tools
• If the misfire continues, inspect and clean the fuel injector for cylinder 1.
• Use a fuel injector cleaner to flush out any deposits.
• If cleaning does not resolve the issue, replace the fuel injector.

5. Compression Test (if needed)

• Tools Required: Compression tester
• If misfire persists after replacing spark plug and ignition coil, perform a compression test.
• Remove the spark plug from cylinder 1 and screw in the compression tester.
• Crank the engine and record the compression reading. Compare with manufacturer specifications.
• If compression is below specifications, further engine diagnosis may be required.