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

Solution

1. Preparation

• Gather tools and parts needed.
• Ensure the vehicle is on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 2 by unscrewing the mounting bolt and lifting it out.
• Remove the spark plug using a spark plug socket and ratchet.
• Inspect the spark plug for wear, carbon buildup, or damage. Replace if necessary.
  • Torque the new spark plug to 13 lb-ft (17.6 Nm) when installing.
• Reinstall the ignition coil after replacing the spark plug.

3. Check and Replace Ignition Coil (if necessary)

• If the spark plug is fine, test the ignition coil for proper resistance using a multimeter.
  • Typical resistance for Honda coils is between 0.4 to 0.6 ohms (primary), and 6.5 to 13.5 k-ohms (secondary).
• Replace the ignition coil if it is out of specification.
• Reinstall the coil onto the spark plug and secure it.

4. Inspect Fuel Injector

• Disconnect the fuel injector connector for cylinder 2.
• Use a noid light to check if the injector is receiving a signal when the engine is cranked.
• If no signal is present, inspect wiring for breaks or corrosion and repair as needed.
• If the injector is faulty, replace it with a new one, ensuring proper seating and connection.

5. Compression Test (if misfire persists)

• If misfire continues, perform a compression test on cylinder 2.
• If the compression is low (below 150 psi), further investigation is required for possible internal engine issues such as a blown head gasket or valve problems.
• Repair as necessary (this may include head gasket replacement or valve adjustments).