why does my Genesis G70 have a check engine light and P0303 code?

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

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

2. Inspect and Replace Ignition Components

1. Remove Engine Cover:

   • Use a socket set to take off any bolts securing the engine cover.
   • Carefully lift off the cover and set it aside.

2. Check and Replace Spark Plug:

   • Remove the ignition coil from cylinder 3 by unscrewing the securing bolts.
   • Pull off the ignition coil and inspect the spark plug.
   • If it appears worn or damaged, replace it with a new spark plug, ensuring it is gapped correctly per manufacturer specifications.

3. Reinstall Ignition Coil:

   • Reinstall the ignition coil on the new spark plug and secure it with the bolts.

3. Inspect and Clean Fuel Injector

1. Remove Fuel Injector:

   • Disconnect the fuel injector wiring harness.
   • Remove the fuel rail bolts to access the injector.
   • Carefully pull the injector from its seat.

2. Clean or Replace Fuel Injector:

   • If cleaning, use a fuel injector cleaner to thoroughly flush the injector.
   • If damaged, replace with a new fuel injector, ensuring O-rings are lubricated and seated correctly.

3. Reinstall Fuel Injector:

   • Reinsert the cleaned or new fuel injector back into the fuel rail and secure it.

4. Compression Test

1. Remove Spark Plug:

   • If not already done, remove the spark plug from cylinder 3.

2. Connect Compression Tester:

   • Insert the compression tester into the spark plug hole.
   • Crank the engine for several seconds and read the compression values.

3. Evaluate Results:

   • Compare the readings with the manufacturer's specifications. If values are low, further investigation is needed.