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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, fuel injector cleaner.
• Safety Warnings: Disconnect the battery before working on electrical systems. Allow the engine to cool before proceeding.

2. Replace Spark Plug

1. Remove Engine Cover: If applicable, unscrew and remove the engine cover to access the ignition components.
2. Disconnect Ignition Coil: Unplug the electrical connector from the ignition coil for cylinder 3.
3. Remove Ignition Coil: Unbolt the ignition coil using a socket and lift it out.
4. Remove Old Spark Plug: Use a spark plug socket to remove the spark plug from cylinder 3.
5. Install New Spark Plug: Apply anti-seize compound to the threads of the new spark plug, then install it hand-tight. Use a torque wrench to tighten to the manufacturer's specification (usually around 13 lb-ft).
6. Reinstall Ignition Coil: Place the ignition coil back and secure it with bolts. Reconnect the electrical connector.

3. Test and Replace Fuel Injector (if necessary)

1. Disconnect Fuel Injector Connector: Unplug the electrical connector from the fuel injector for cylinder 3.
2. Remove Fuel Injector: Unscrew and carefully pull out the fuel injector.
3. Inspect and Clean: Check the injector for any blockage. If dirty, use a fuel injector cleaner or replace it with a new one.
4. Reinstall Fuel Injector: Insert the cleaned or new fuel injector back into its place and reconnect the electrical connector.

4. Check Compression (if misfire persists)

1. Remove Spark Plug: Take out the spark plug from cylinder 3 again.
2. Insert Compression Tester: Screw in the compression tester into the spark plug hole.
3. Crank Engine: Crank the engine a few times to get a reading.
4. Compare Readings: Check the compression against manufacturer specifications (usually around 180-200 psi). If low, further investigation is needed for internal engine issues.