my Genesis G70 is misfiring, what does code P0303 mean?

Learn how to diagnose and fix P0303 cylinder 3 misfire in Genesis G70. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on the electrical components.

2. Inspect and Replace Ignition Components

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the engine cover (if applicable) to access the ignition components.
• Using the spark plug socket, remove the spark plug from cylinder 3.
• Inspect the spark plug for wear or damage and replace if necessary.
• Check the ignition coil for cylinder 3, ensuring the connector is secure and there are no visible damages. Replace the ignition coil if faulty.

3. Fuel Injector Inspection and Testing

• Tools Required: Noid light or multimeter.
• Disconnect the fuel injector connector from cylinder 3.
• Use a noid light to check for injector pulse; if the light does not illuminate, further diagnose the wiring or ECM.
• If the pulse is present, remove the fuel injector and inspect it for dirt or blockage. Clean or replace the injector as needed.

4. Compression Test

• Tools Required: Compression tester.
• Remove the spark plug from cylinder 3 again.
• Insert the compression tester into the spark plug hole and crank the engine to measure the compression.
• Compare the readings against the manufacturer’s specifications. If low, further diagnosis is needed for potential internal engine issues.

5. Reassemble and Test

• Reinstall all components in reverse order of removal.
• Reconnect the battery.
• Clear the fault codes from the OBD-II scanner.
• Start the engine and monitor for any misfire codes or symptoms.