how to fix P0303 misfire code in Honda Accord 9th Generation (2013-2017)

Solution

1. Preparation

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

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, torque wrench
• Remove the ignition coil by unbolting it and disconnecting the electrical connector.
• Remove the spark plug using a spark plug socket.
• Inspect the spark plug for signs of wear, such as carbon fouling or excessive gap.
• Replace with a new spark plug if necessary, ensuring the gap is set to manufacturer specifications (typically 0.043 inches for Honda).
• Torque the new spark plug to 13 lb-ft.

3. Test and Replace Ignition Coil (if necessary)

• Tools Required: Multimeter
• Check the resistance of the ignition coil using a multimeter (should be within manufacturer specifications).
• If the ignition coil is faulty, replace it with a new one.
• Reinstall the ignition coil and reconnect the electrical connector.

4. Inspect Fuel Injector

• Remove the fuel rail to access the fuel injector for cylinder 3.
• Test the injector for proper spray pattern and flow using a fuel injector tester.
• Clean or replace the injector as needed.
• Reassemble the fuel rail after servicing the injector.

5. Perform Compression Test

• Tools Required: Compression gauge
• Remove the spark plug from cylinder 3 and insert the compression gauge.
• Crank the engine a few times and record the reading.
• Compare the compression reading with the specifications (typically around 180 psi).
• If compression is low, further investigation is needed for potential internal engine issues.