how to fix a Honda Accord with a P0303 code

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the negative battery terminal to avoid electrical shorts.

2. Inspect and Replace Spark Plug

• Remove the engine cover if necessary.
• Locate the ignition coil for cylinder 3 (refer to service manual for location).
• Disconnect the electrical connector and remove the ignition coil (use a socket set).
• Remove the spark plug using a spark plug socket and ratchet.
• Inspect the spark plug for carbon buildup or damage. Replace if necessary.
• Install a new spark plug (torque to manufacturer's specifications, typically 13 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Check and Replace Fuel Injector

• Disconnect the fuel injector connector for cylinder 3.
• Remove the fuel rail per service manual instructions.
• Carefully remove the fuel injector (usually requires gentle prying).
• Inspect the injector for clogs or wear. Replace if necessary.
• Reinstall the fuel injector and fuel rail, ensuring all seals are properly seated.

4. Compression Test

• Remove the spark plug for cylinder 3.
• Insert the compression tester into the spark plug hole.
• Crank the engine several times to get a reading.
• Compare the reading to the manufacturer's specifications; if low, further investigation is needed.