how to diagnose a P0301 misfire code on Honda Accord Eleventh Generation (2023-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool before beginning work.

2. Remove Spark Plug

• Use a socket wrench with the appropriate spark plug socket to remove the spark plug from cylinder 1.
• Inspect the spark plug for wear or damage; replace if necessary.
• Torque specification: Install the new spark plug to 13 lb-ft (17.6 Nm).

3. Inspect and Test Ignition Coil

• Disconnect the ignition coil connector and remove the coil from cylinder 1.
• Use a multimeter to check the primary and secondary resistance of the ignition coil.
• If the ignition coil is faulty, replace it with a new one.

4. Check Fuel Injector

• Remove the fuel injector connector for cylinder 1.
• Use a noid light to check for proper electrical signal to the injector.
• If there's no signal, inspect the wiring; if the injector is faulty, replace it.

5. Perform Compression Test

• Remove the fuel pump fuse to prevent fuel delivery during the test.
• Install a compression gauge in cylinder 1 and crank the engine.
• The compression reading should be within the manufacturer's specifications (typically around 180-200 psi). Replace if low.

6. Reassemble and Reconnect

• Reinstall all components in reverse order.
• Reconnect the negative battery terminal.
• Clear the error codes using the OBD-II scanner.