how to troubleshoot Honda Civic 10th Generation (2016-2021) P0302 misfire code?

Solution

1. Preparation

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

2. Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench, dielectric grease.
• Remove the ignition coil by unscrewing it and disconnecting the electrical connector.
• Remove the spark plug using the spark plug socket. Inspect for damage, carbon build-up, or oil fouling.
• Install a new spark plug with the correct gap (0.044 inches for Honda Civic).
• Apply dielectric grease to the ignition coil boot before reinstalling.

3. Test or Replace Ignition Coil

• Tools Required: Multimeter (if testing), new ignition coil (if replacing).
• If you swapped the ignition coil previously and the code followed, replace the ignition coil for cylinder 2.
• If testing, ensure the coil has the correct resistance values as per Honda specifications.

4. Inspect or Replace Fuel Injector

• Tools Required: Fuel injector removal tool, new fuel injector (if replacing).
• Disconnect the fuel line and electrical connector from the fuel injector.
• Remove the fuel injector from its rail. Inspect for clogs or damage.
• If necessary, replace with a new fuel injector and reassemble.

5. Perform a Compression Test

• Tools Required: Compression tester.
• Remove the spark plug for cylinder 2 and install the compression tester.
• Crank the engine and record the compression reading. Compare with specifications (typically around 180 psi).
• If compression is low, further investigate potential internal engine issues (e.g., head gasket, piston rings).