how to fix the P0303 code on my Honda Accord 9th Generation (2013-2017)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the engine is cool and disconnect the negative battery cable.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 3.
  • Tools: Ratchet with socket, extension.
• Remove the spark plug from cylinder 3 using a spark plug socket.
  • Inspect the spark plug for wear or damage.
  • If worn, replace with a new spark plug (check gap specifications).
• Reinstall the new spark plug and torque to manufacturer specifications (typically around 13 lb-ft).

3. Inspect and Replace Ignition Coil

• If the spark plug is in good condition, test the ignition coil with a multimeter.
  • Check primary and secondary resistance values.
  • If faulty, replace with a new ignition coil specific to the Honda Accord.
• Reinstall the ignition coil and ensure connections are secure.

4. Check and Clean Fuel Injector

• Disconnect the fuel injector connector for cylinder 3.
• Remove the fuel injector from the rail (may require removal of the fuel rail).
• Inspect for clogs or damage.
• Clean the injector with a specialized fuel injector cleaner or replace with a new fuel injector if needed.
• Reinstall the fuel injector and reconnect the fuel rail.

5. Compression Test and Repair

• If misfire persists, perform a compression test on cylinder 3.
  • Tools: Compression tester.
• If compression is low, further diagnostics are needed (valve adjustment, head gasket replacement, etc.).