how to fix P0301 code on Honda Civic 9th Generation (2012-2015)

Solution

1. Preparation

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

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1.
• Remove the spark plug using a spark plug socket and ratchet.
• Inspect the spark plug for wear or damage; replace if necessary.
• Install a new spark plug (OEM recommended gap: 0.044 inches) and torque to 13 lb-ft (17.6 Nm).
• Reinstall the ignition coil.

3. Inspect and Replace Ignition Coil (if necessary)

• If the spark plug is in good condition but the misfire persists, remove the ignition coil from cylinder 1.
• Test the ignition coil with a multimeter (check primary and secondary resistance as per specifications).
• Replace the ignition coil with a new one if it is faulty.
• Reinstall the ignition coil.

4. Check Fuel Injector

• Disconnect the wiring harness from the fuel injector for cylinder 1.
• Use a multimeter to test the injector's resistance (should be around 12-16 ohms).
• If the injector is faulty, replace it with a new one.
• Reconnect the wiring harness.

5. Perform Compression Test (if misfire persists)

• Remove the spark plug from cylinder 1.
• Attach a compression gauge to the spark plug hole.
• Crank the engine and record the compression reading (should be within manufacturer specifications, typically 180-200 psi).
• If compression is low, investigate potential internal engine issues (e.g., valve seating, piston rings).

6. Reconnect Battery

• After all repairs are completed, reconnect the negative battery terminal.
• Clear the P0301 code using the OBD-II scanner.