how to fix P0301 misfire code in my Honda Civic 11th Generation (2022-Present)

Solution

1. Preparation

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

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1:
  • Disconnect the electrical connector.
  • Remove the mounting bolts using a socket set.
• Remove the spark plug:
  • Use a spark plug socket to unscrew and remove the spark plug.
• Inspect the spark plug for wear (carbon buildup, cracking, or damage).
• If necessary, replace the spark plug with a new one that meets OEM specifications. Torque to manufacturer’s specifications (usually around 13-16 lb-ft).

3. Check and Replace Ignition Coil

• Inspect the ignition coil:
  • Check for physical damage or signs of wear.
• If faulty, replace the ignition coil:
  • Install the new ignition coil in reverse order of removal.
  • Reconnect the electrical connector and secure it with bolts (torque to specifications).

4. Test and Replace Fuel Injector

• Check the fuel injector for cylinder 1:
  • Disconnect the fuel injector connector.
  • Use a noid light to check for proper signal (it should flash).
• If the injector is not functioning, replace it:
  • Remove the fuel rail if necessary to access the injector.
  • Install the new fuel injector, ensuring proper seating.
  • Reconnect the fuel line and electrical connector.

5. Compression Test

• Perform a compression test on cylinder 1:
  • Remove the spark plug and install the compression tester.
  • Crank the engine and record the pressure reading.
• If the compression is low, further diagnosis of the engine's internals may be needed (e.g., valve issues, piston rings).