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

Solution

1. Preparation

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

2. Spark Plug Inspection and Replacement

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Remove the ignition coil for cylinder 1 by unbolting it and lifting it out.
• Remove the spark plug using the spark plug socket. Inspect it for wear or damage.
  • If the spark plug is fouled or worn, replace it with a new one.
• Torque the new spark plug to the manufacturer’s specification (typically around 13 lb-ft).

3. Ignition Coil Testing and Replacement

• If the spark plug is in good condition, test the ignition coil by swapping it with an adjacent cylinder's coil.
• Reconnect the battery, start the engine, and check if the misfire code changes to the cylinder where the coil was moved.
  • If the misfire follows the coil, replace the ignition coil for cylinder 1.
• If no change occurs, the ignition coil is likely functioning properly.

4. Fuel Injector Inspection

• Check the fuel injector for cylinder 1 for clogs or electrical issues.
• If necessary, remove the fuel injector harness and test it for continuity with a multimeter.
• Clean or replace the fuel injector if it is faulty.

5. Compression Test

• Attach a compression gauge to cylinder 1 after removing the spark plug.
• Crank the engine and note the compression reading.
• Compare the reading to manufacturer specifications (typically around 180 psi).
• If the compression is low, further investigation into potential mechanical issues is needed.