how to fix P0301 code on Honda Civic 10th Generation (2016-2021)

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, socket set, torque wrench, compression tester, noid light or fuel pressure gauge.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal for safety.

2. Replace Spark Plug

1. Remove the ignition coil from cylinder 1 by unbolting it and disconnecting the electrical connector.
2. Remove the spark plug using a spark plug socket and ratchet.
3. Inspect the old spark plug for signs of wear (fouling, burning).
4. Install a new spark plug, ensuring it is gapped correctly to manufacturer specifications (usually around 0.044 inches for Honda).
5. Torque the spark plug to the manufacturer's specified value (typically around 13 lb-ft).

3. Replace Ignition Coil

1. If the ignition coil is faulty, install a new ignition coil for cylinder 1.
2. Connect the electrical connector to the new ignition coil and secure it in place.
3. Reconnect the negative battery terminal.

4. Test Fuel Injector

1. If fuel delivery is suspected, replace or clean the fuel injector for cylinder 1.
2. Reconnect the fuel injector and ensure it is properly seated.
3. If testing with a noid light, attach it to the injector connector to check for signal.

5. Reassemble and Clear Codes

1. Reinstall any components removed during the process.
2. Use the OBD-II scanner to clear the P0301 code from the vehicle's computer.
3. Start the engine and monitor for any reoccurring codes.