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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a level surface, and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical issues.

2. Inspect and Replace Spark Plug

1. Remove the engine cover if applicable.
2. Locate the spark plug for cylinder 2 (refer to the owner's manual for cylinder layout).
3. Use a socket wrench to remove the spark plug.
4. Inspect the spark plug for wear, deposits, or damage; replace it if necessary.
5. Set the gap of the new spark plug to the manufacturer's specifications (typically around 0.044 inches for a Honda Civic).
6. Install the new spark plug and torque it to the recommended value (typically around 13 lb-ft).
7. Reconnect any components removed for access.

3. Test and Replace Ignition Coil

1. Locate the ignition coil for cylinder 2.
2. Disconnect the electrical connector from the ignition coil.
3. Use a multimeter to test the primary and secondary resistance of the ignition coil; compare results to specifications.
4. If faulty, remove the ignition coil and install a new one.
5. Reconnect the electrical connector securely.

4. Inspect and Clean or Replace Fuel Injector

1. Locate the fuel injector for cylinder 2.
2. Disconnect the fuel injector electrical connector.
3. Perform a visual inspection for clogs or leaks; clean it with a suitable injector cleaner or replace it if needed.
4. Reconnect the fuel injector connector.

5. Compression Test

1. Remove the spark plug from cylinder 2.
2. Insert the compression tester into the spark plug hole.
3. Crank the engine to measure compression; refer to specifications for acceptable values (typically around 180 psi).
4. If compression is low, further diagnosis of internal engine components may be necessary.