how to fix P0303 misfire code in Honda Accord 10th Generation (2018-2022)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Park the vehicle on a flat surface and engage the parking brake.
• Disconnect the negative battery terminal to prevent electrical shocks.

2. Inspect and Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Remove the ignition coil from cylinder 3.
• Remove the spark plug using a spark plug socket.
• Inspect the spark plug for wear or fouling; replace it if necessary.
• Install the new spark plug and torque it to the manufacturer’s specification (typically around 13-16 lb-ft).
• Reinstall the ignition coil.

3. Test and Replace Ignition Coil (if needed)

• Reconnect the negative battery terminal.
• Use a multimeter to check the resistance of the ignition coil. Compare results with manufacturer specifications.
• If the coil is faulty, remove it and replace it with a new one.
• Reconnect all connectors.

4. Inspect and Clean Fuel Injector

• Tools Required: Fuel injector cleaner, basic hand tools.
• Remove the fuel injector from cylinder 3 using a wrench.
• Clean the injector using a fuel injector cleaner or replace it if it’s clogged or defective.
• Reinstall the fuel injector, ensuring proper seals are installed.

5. Perform a Compression Test

• Tools Required: Compression gauge.
• Insert the compression gauge into the spark plug hole of cylinder 3.
• Crank the engine to obtain a reading. Compare results with manufacturer specifications.
• If the compression is low, further investigation into mechanical issues is required.