how to fix P0303 code in my Honda Civic 11th Generation (2022-Present)

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, compression tester, socket set, torque wrench.
• Safety Warnings: Disconnect the negative battery terminal before working on electrical components.

2. Replace Spark Plug

• Remove the engine cover if necessary.
• Disconnect the ignition coil connector for cylinder 3.
• Remove the ignition coil using a socket set.
• Inspect the spark plug; replace if worn or fouled.
• Install the new spark plug to the manufacturer’s torque specification (typically 13 lb-ft).
• Reattach the ignition coil and its connector.

3. Inspect and Test Ignition Coil

• Test the ignition coil’s resistance using a multimeter according to the specifications in the service manual.
• If the resistance is out of range, replace the ignition coil.
• Reinstall the ignition coil and reconnect the plug.

4. Test Fuel Injector

• Disconnect the fuel injector connector for cylinder 3.
• Use a noid light to check for injector pulse while cranking the engine.
• If no pulse, test the circuit with a multimeter; if faulty, replace the fuel injector.
• If the injector is faulty, remove it and replace it with a new one, ensuring proper seating and connection.

5. Perform Compression Test

• Remove the spark plug for cylinder 3 and insert the compression tester.
• Crank the engine and record the compression reading. It should be within the manufacturer's specified range (usually around 180-200 psi).
• If the compression is low, further diagnosis is needed (e.g., valve issues, head gasket).