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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Safety gear: gloves and safety glasses.
• Disconnect the battery negative terminal to prevent electrical shorts.

2. Replace Spark Plug

• Remove the engine cover if applicable.
• Locate cylinder 1 spark plug (usually the front left when facing the engine).
• Use a socket wrench to unscrew the old spark plug and remove it.
• Inspect the spark plug's condition (look for carbon buildup, cracks, or excessive wear).
• Install a new spark plug (use the manufacturer-recommended type) and torque to specification (usually around 13-16 ft-lbs).

3. Inspect and Replace Ignition Coil

• Disconnect the electrical connector from the ignition coil.
• Remove the bolts securing the ignition coil and lift it out.
• Inspect for signs of damage or wear.
• Install a new ignition coil and secure it with bolts (torque to manufacturer specifications).
• Reconnect the electrical connector.

4. Test and Clean Fuel Injector

• Remove the fuel injector connector from cylinder 1.
• Use a noid light to check for proper electrical signal to the injector.
• If the injector is faulty, remove it using a fuel injector puller or appropriate tool.
• Clean the injector using an ultrasonic cleaner or replace it with a new injector.
• Reinstall and reconnect the injector.

5. Compression Test

• Reconnect the battery.
• Perform a compression test on cylinder 1 using a compression gauge.
• If compression is low, further investigation of the piston rings or valves may be needed.