how to fix P0304 misfire code in Honda Accord 10th Generation (2018-2022)

Learn how to diagnose and fix P0304 cylinder 4 misfire in Honda Accord 10th Generation. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative terminal of the battery.

2. Inspect Spark Plug

• Tools Required: Socket set, torque wrench
• Remove the ignition coil and spark plug for cylinder four.
• Inspect the spark plug for signs of wear or fouling.
• Replace the spark plug if damaged.
• Reinstall the spark plug with a torque of 13 lb-ft (17.6 Nm).

3. Check Ignition Coil

• Tools Required: Multimeter
• Test the ignition coil’s primary and secondary resistance using a multimeter.
• If the ignition coil is faulty, replace it with a new one.
• Reinstall the ignition coil securely.

4. Test Fuel Injector

• Tools Required: Fuel pressure gauge, injector cleaner
• Disconnect the fuel injector connector and check for proper voltage while cranking the engine.
• If the injector is not functioning, replace it.
• Clean the fuel injector using a professional fuel injector cleaner if applicable.

5. Compression Test

• Tools Required: Compression tester
• Remove the spark plug for cylinder four.
• Insert the compression tester and crank the engine.
• Compare the compression reading to manufacturer specifications; replace or repair the engine if readings are low.

6. Inspect for Vacuum Leaks

• Visual inspection of vacuum lines and intake manifold.
• Use a smoke machine or carburetor cleaner to check for leaks.
• Repair or replace any damaged vacuum lines or gaskets.