how to fix P0301 misfire code in Honda Accord 9th Generation (2013-2017)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery to prevent electrical shorts.
• Ensure the engine is cool before starting work.

2. Replace Spark Plug

1. Remove the ignition coil from cylinder 1:
   • Unscrew the mounting bolts using a socket set.
   • Carefully lift the ignition coil straight out.
2. Remove the spark plug:
   • Use a spark plug socket and ratchet to unscrew the spark plug.
   • Inspect the old spark plug for wear, carbon buildup, or damage.
3. Install a new spark plug:
   • Gap the new spark plug to manufacturer specifications (typically 0.043 inches for Honda).
   • Screw in the new spark plug by hand, then tighten to 13 lb-ft (17.6 Nm) torque.

3. Test and Replace Ignition Coil (if necessary)

1. Swap the ignition coil from cylinder 1 with one from a different cylinder.
2. Clear the P0301 code using the OBD-II scanner and run the engine.
3. If the misfire moves to the new cylinder, replace the ignition coil with a new one.
   • Follow removal steps similar to those for the spark plug.

4. Inspect and Replace Fuel Injector (if necessary)

1. Disconnect the electrical connector and fuel line from the fuel injector for cylinder 1.
2. Remove the fuel injector by unscrewing the retaining clips or bolts.
3. Install the new fuel injector and reconnect the fuel line and electrical connector.
4. Clear codes and test the engine operation again.

5. Final Checks

• Reconnect the battery.
• Start the engine and let it reach operating temperature.
• Monitor for any check engine light re-illuminating.