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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool before working on it.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Compression tester
• Fuel injector cleaning kit

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1.
• Unscrew and remove the spark plug using a socket wrench.
• Inspect the spark plug for wear, fouling, or damage.
• If necessary, replace the spark plug with a new one. Recommended gap: 0.044 inches (1.1 mm).
• Reinstall the ignition coil, ensuring proper torque to manufacturer specifications (usually around 7.2 lb-ft).

3. Test and Clean Fuel Injector

• Disconnect the fuel injector connector for cylinder 1.
• Use a multimeter to check the injector's resistance; it should typically be between 12-16 ohms.
• If the injector is faulty, replace it. Otherwise, proceed to clean it using a fuel injector cleaning kit.
• Reconnect the fuel injector and ensure it seats properly.

4. Perform Compression Test

• Remove the spark plug from cylinder 1.
• Insert the compression tester into the spark plug hole.
• Crank the engine for a few seconds and record the compression reading.
• Compare the reading to the specifications (typically around 180 psi). If the compression is low, further investigation is required for potential internal engine issues.

5. Inspect for Vacuum Leaks

• Visually inspect the intake manifold and hoses for cracks or disconnections.
• Use a smoke machine or carburetor cleaner while the engine is running to detect any vacuum leaks.
• Repair or replace any faulty components as necessary.