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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, fuel injector cleaning kit.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shock.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 2:
  1. Unplug the electrical connector from the ignition coil.
  2. Remove the mounting bolts using a socket set.
• Remove the spark plug:
  1. Use a spark plug socket to unscrew and remove the spark plug from cylinder 2.
  2. Inspect the old spark plug for signs of wear or fouling.
• Install a new spark plug:
  1. Gap the new spark plug according to the manufacturer’s specifications (typically around 0.044 inches).
  2. Install the new spark plug and torque it to the manufacturer-recommended value (usually around 13-16 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Replace Ignition Coil (if necessary)

• If the ignition coil is found faulty during diagnosis, replace it:
  1. Remove the old coil as outlined above.
  2. Install the new ignition coil, ensuring it is seated properly.
  3. Reconnect the electrical connector securely.

4. Clean or Replace Fuel Injector (if necessary)

• If the fuel injector is suspected to be faulty:
  1. Disconnect the fuel line and electrical connector from the injector.
  2. Remove the fuel injector from the rail.
  3. Clean the injector using a fuel injector cleaning kit or replace it with a new one.
  4. Reinstall the injector and reconnect the fuel line and electrical connector.

5. Conduct Compression Test (if necessary)

• If misfire persists:
  1. Remove the spark plug from cylinder 2.
  2. Insert the compression tester into the spark plug hole.
  3. Crank the engine and read the compression value. Compare it to specifications (usually around 180 psi).
  4. If compression is low, further diagnosis on the engine may be required.