how to fix P0303 misfire code on my Genesis G70 IG (2017-2023)

Learn how to diagnose and fix P0303 cylinder 3 misfire in Genesis G70 (2017-2023). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery negative terminal to prevent electrical shorts.
• Allow the engine to cool down if it has been running.

2. Inspect and Replace Ignition Coil

1. Remove the Engine Cover (if applicable)
   • Use a socket set to remove bolts securing the engine cover.
2. Disconnect the Ignition Coil
   • Unplug the electrical connector from the ignition coil on cylinder 3.
3. Remove the Ignition Coil
   • Unscrew the ignition coil using a socket wrench and lift it out.
4. Install New Ignition Coil
   • Place the new ignition coil into the cylinder head and torque it to the manufacturer’s specification (usually around 15-20 Nm).
5. Reconnect the Electrical Connector
   • Ensure the connector clicks into place securely.

3. Inspect and Replace Spark Plug

1. Remove the Spark Plug
   • Using a spark plug socket, unscrew and remove the spark plug from cylinder 3.
2. Inspect the Spark Plug
   • Look for signs of fouling, wear, or incorrect gap. Replace if necessary.
3. Install New Spark Plug
   • Set the gap according to manufacturer specifications (usually around 0.028-0.031 inches).
   • Hand-tighten the spark plug, then torque it to the manufacturer’s specifications (typically around 20-30 Nm).

4. Inspect Fuel Injector

1. Remove Fuel Injector Connector
   • Unplug the fuel injector connector on cylinder 3.
2. Test the Fuel Injector
   • Use a multimeter to check for proper resistance (should be around 12-16 ohms).
3. Replace Fuel Injector (if faulty)
   • Remove any retaining clips and unscrew the injector from the rail.
   • Install a new injector, ensuring proper seating and sealing.