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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, noid light, multimeter, basic hand tools.
• Clear the error codes after diagnostics are completed.

2. Replace Spark Plug

1. Remove Engine Cover: If applicable, remove the engine cover to access the ignition components.
2. Disconnect Ignition Coil: Unplug the electrical connector from the ignition coil on cylinder 2.
3. Remove Ignition Coil: Unscrew the ignition coil using the socket set and carefully pull it out.
4. Remove Spark Plug: Use a spark plug socket to unscrew and remove the spark plug. Inspect for damage or fouling.
5. Install New Spark Plug: Insert a new spark plug (ensure proper gap) and torque it to the manufacturer’s specifications (typically around 13 lb-ft).
6. Reinstall Ignition Coil: Position the ignition coil back in, screw it in, and reconnect the electrical connector.

3. Replace Fuel Injector (if needed)

1. Remove Fuel Rail: Relieve fuel pressure using the fuel pressure relief valve, then disconnect the fuel lines and unbolt the fuel rail.
2. Remove Old Injector: Pull the fuel injector out of cylinder 2 from the fuel rail.
3. Install New Injector: Lubricate the O-ring of the new injector with clean engine oil and insert it into the fuel rail and then into the cylinder.
4. Reinstall Fuel Rail: Bolt the fuel rail back in place, reconnect the fuel lines, and ensure there are no leaks.

4. Check Compression (if needed)

1. Remove Spark Plug: Remove the spark plug from cylinder 2 once again.
2. Connect Compression Tester: Screw the compression tester into the spark plug hole.
3. Crank Engine: Crank the engine for a few seconds to get a reading.
4. Record Compression: Note the compression reading and compare with factory specifications (typically around 180 psi).
5. Reinstall Spark Plug: If compression is good, reinstall the spark plug.