how to fix P0301 cylinder 1 misfire code in Honda Accord 10th Generation (2018-2022)

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative battery terminal to prevent electrical shock.
• Allow engine to cool completely before starting work.

2. Replace Spark Plug

• Remove the ignition coil cover (if applicable).
• Unplug the wiring harness from the ignition coil.
• Unscrew and remove the ignition coil from cylinder 1.
• Use a spark plug socket to remove the old spark plug.
• Inspect the spark plug for signs of wear, fouling, or incorrect gap (0.043 inches for Honda Accord).
• Install a new spark plug, tightening it to 13 lb-ft (17.5 Nm).
• Reinstall the ignition coil and connect the wiring harness.

3. Inspect and Replace Ignition Coil (if necessary)

• If the ignition coil shows signs of damage or was previously faulty, replace it.
• Remove the old ignition coil and install a new one.
• Ensure it is securely fastened and connected properly.

4. Check Compression

• Remove the spark plug from cylinder 1.
• Attach the compression tester to the spark plug hole.
• Crank the engine to take a compression reading; it should be within manufacturer specifications (typically around 180 psi).
• If compression is low, further inspection of valves and piston rings may be necessary.

5. Test Fuel Injector

• If misfire persists, inspect the fuel injector for cylinder 1.
• Use a multimeter to check for proper resistance (usually around 12-16 ohms).
• If faulty, replace the fuel injector, ensuring to clean any debris from the intake manifold before installation.