how to diagnose a P0302 code on my Honda Civic 11th Generation (2022-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Remove the engine cover if necessary.
• Locate and remove the spark plug wire or ignition coil for cylinder 2.
• Use a spark plug socket to remove the spark plug.
• Inspect the spark plug for wear or fouling. Replace it if necessary (use manufacturer-recommended spark plug).
• Install the new spark plug with a torque value of 13 lb-ft (17.6 Nm) and reconnect the ignition coil or spark plug wire.

3. Inspect and Replace Ignition Coil

• If the spark plug is in good condition, test the ignition coil by swapping it with a working coil from another cylinder.
• If the misfire code shifts to that cylinder, replace the ignition coil for cylinder 2.
• Install the new ignition coil, ensuring it is securely connected.

4. Fuel Injector Inspection and Cleaning

• If the ignition system is functioning, disconnect the fuel injector connector for cylinder 2.
• Use a multimeter to test the fuel injector's resistance (should be within manufacturer specifications).
• Clean the fuel injector using a fuel injector cleaner or replace it if found defective.

5. Compression Test

• If misfire persists, perform a compression test on cylinder 2.
• Remove the spark plug and attach a compression gauge.
• Have an assistant crank the engine to get the reading.
• Compare the results with manufacturer specifications. If low, investigate further for potential mechanical issues.