how to fix P0302 misfire code on Honda Civic 10th Generation (2016-2021)

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Compression tester
• Noid light or multimeter
• Screwdriver set

2. Replace Spark Plug

• Remove the engine cover if applicable.
• Disconnect the ignition coil connector.
• Unbolt the ignition coil and remove it from the spark plug.
• Use a spark plug socket to remove the old spark plug from cylinder number 2.
• Inspect the spark plug for wear; replace if necessary.
• Install the new spark plug, tightening it to the manufacturer's specified torque (typically around 13-16 lb-ft).
• Reinstall the ignition coil and reconnect the connector.

3. Inspect and Replace Ignition Coil

• If the misfire persists after replacing the spark plug, remove the ignition coil.
• Inspect the coil for cracks or carbon tracking.
• If defective, replace the ignition coil with a new one and reinstall it.

4. Perform Compression Test

• Remove the spark plug again to access the cylinder.
• Insert the compression tester into the spark plug hole.
• Crank the engine and note the compression reading; it should be within specification (typically 180-210 psi).
• If compression is low, further investigation into engine internals may be necessary.

5. Check Fuel Injector

• Disconnect the fuel injector connector for cylinder number 2.
• Connect a noid light to the injector connector to check for pulse while cranking the engine.
• If no pulse is detected, further diagnose the fuel injector circuit.
• If the injector is faulty, replace it and reconnect the wiring.