how to fix P0302 code in Honda Civic 9th Generation (2012-2015) misfire

Solution

1. Preparation

• Gather all necessary tools and parts before starting the repair.
• Tools Required: Socket set, torque wrench, spark plug socket, multimeter, compression tester.
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Replace Spark Plug

• Sub-steps:
  1. Disconnect the negative battery terminal to prevent electrical shock.
  2. Remove the engine cover if applicable.
  3. Locate the spark plug for cylinder 2 (consult the owner's manual for exact location).
  4. Use a spark plug socket to carefully remove the old spark plug.
  5. Inspect the old spark plug for wear; replace if necessary.
  6. Gap the new spark plug according to specifications (usually between 0.043-0.047 inches).
  7. Install the new spark plug and torque to the manufacturer’s specifications (typically around 13 lb-ft).
  8. Reattach the ignition coil and ensure it seats properly.

3. Test and Replace Ignition Coil (if necessary)

• Sub-steps:
  1. Disconnect the ignition coil connector and remove the coil from cylinder 2.
  2. Use a multimeter to test the coil’s primary and secondary resistance (consult specifications for values).
  3. If the coil is faulty, replace it with a new one.
  4. Reinstall the ignition coil and reconnect the connector.

4. Inspect and Replace Fuel Injector (if necessary)

• Sub-steps:
  1. Disconnect the fuel injector connector for cylinder 2.
  2. Use a multimeter to check the injector's resistance (typically around 12-16 ohms).
  3. If the injector is faulty, remove the fuel rail and replace the injector.
  4. Reinstall the fuel rail and ensure all connections are secure.

5. Check for Vacuum Leaks

• Sub-steps:
  1. Inspect all vacuum hoses and connections around the intake manifold and throttle body.
  2. Use a smoke machine or carburetor cleaner to detect any leaks.
  3. Repair or replace any faulty hoses or connections as necessary.

6. Perform Compression Test (if misfire persists)

• Sub-steps:
  1. Remove the spark plug from cylinder 2 and install the compression tester.
  2. Crank the engine several times and record the compression reading.
  3. If the reading is significantly lower than other cylinders, further investigation into mechanical issues may be necessary.