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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before beginning work.

2. Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Remove the ignition coil from cylinder 2 by unscrewing the mounting bolts and disconnecting the electrical connector.
• Remove the spark plug using a spark plug socket.
• Inspect the old spark plug for wear or fouling and compare it with manufacturer specifications.
• Install a new spark plug at the specified gap (consult the owner’s manual for correct gap).
• Torque the spark plug to the manufacturer’s specification (typically around 13 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Check/Replace Ignition Coil

• If the spark plug replacement does not resolve the issue, test the ignition coil for cylinder 2.
• Tools Required: Multimeter.
• Using a multimeter, check the primary and secondary resistance of the coil against manufacturer specifications.
• If the coil is faulty, replace it with a new one.
• Reinstall the ignition coil and reconnect the electrical connector.

4. Inspect/Replace Fuel Injector

• If misfire persists, inspect the fuel injector for cylinder 2.
• Tools Required: Fuel injector puller (if necessary), cleaner.
• Disconnect the fuel injector electrical connector and fuel line (be cautious of fuel spill).
• Remove the fuel injector and inspect it for clogs or damage.
• Clean the injector using a fuel injector cleaner or replace it if necessary.
• Reinstall the injector and reconnect the fuel line and electrical connector.

5. Perform Compression Test

• If misfire continues, perform a compression test on cylinder 2.
• Tools Required: Compression tester.
• Remove the spark plug from cylinder 2 and install the compression tester.
• Crank the engine and read the compression value.
• Compare the reading to manufacturer specifications (usually around 180 psi).
• If compression is low, further investigation into potential internal engine issues is required.