how to diagnose P0301 code on Honda Accord 10th Generation (2018-2022)

Solution

1. Preparation

• Gather tools and parts required.
• Ensure the engine is off and cool before starting work.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Replace Spark Plug

• Tools Required: Spark plug socket, torque wrench, gap gauge.
• Remove the ignition coil for cylinder 1 by unscrewing the retaining bolts and disconnecting the electrical connector.
• Unscrew the old spark plug using the spark plug socket.
• Inspect the spark plug for wear; if damaged or fouled, replace it with a new spark plug, ensuring the gap is set to the manufacturer's specifications (typically around 0.043 inches for Honda).
• Torque the new spark plug to the specifications (usually around 13 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Inspect and Replace Ignition Coil (if necessary)

• If the ignition coil shows signs of wear or if the misfire follows the coil after swapping, replace the ignition coil for cylinder 1 with a new one.
• Reconnect the ignition coil connector and ensure it is securely fastened.

4. Clean or Replace Fuel Injector (if necessary)

• If the fuel injector for cylinder 1 is found to be faulty, remove it by disconnecting the electrical connector and unscrewing any retaining clips.
• Either clean the injector using an appropriate cleaner or replace it with a new injector.
• Reinstall the injector and connect the electrical connector.

5. Verify Cylinder Compression

• If compression is low, further investigation is needed to determine if there are issues with valves, piston rings, or head gasket.
• If compression is acceptable, proceed with reassembly.

6. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear any stored codes.