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

Solution

1. Preparation

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

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 2 by unplugging the electrical connector and unscrewing the mounting bolt.
• Carefully pull out the spark plug using a spark plug socket.
• Inspect the spark plug for wear or fouling. Replace it if necessary.
• Install the new spark plug by hand to avoid cross-threading, and torque to specifications (typically 13 lb-ft for Honda).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Test and Replace Ignition Coil (if necessary)

• Use a multimeter to test the resistance of the ignition coil. Compare readings to manufacturer specifications.
• If the coil is faulty, remove it and replace it with a new one.
• Reinstall the ignition coil and reconnect the electrical connector.

4. Inspect and Clean/Replace Fuel Injector

• Remove the fuel rail to access the fuel injector for cylinder 2.
• Inspect the injector for any clogs; clean it using an appropriate injector cleaner or replace it if necessary.
• Reinstall the fuel rail and ensure all connections are secure.

5. Compression Test (if misfire persists)

• Remove the spark plug from cylinder 2 and insert the compression tester.
• Crank the engine for a few seconds and record the compression reading.
• Compare this reading with the specifications (usually around 190-220 psi for Honda engines).
• If compression is low, further diagnostics on the engine internals may be required.