how to fix P0303 misfire code in Skoda Octavia NFL (2020-Present)

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

Solution

1. Preparation

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

2. Inspect and Replace Ignition Components

• Tools Required: Socket set, torque wrench, spark plug socket
• Remove the ignition coil from cylinder 3:
  1. Unscrew the bolts securing the ignition coil.
  2. Gently pull the ignition coil out of the spark plug well.
• Inspect the spark plug for wear. If necessary, replace with a new spark plug:
  1. Use the spark plug socket to remove the old spark plug.
  2. Apply anti-seize lubricant to the threads of the new spark plug.
  3. Torque the new spark plug to the manufacturer's specification (typically around 20 Nm).
• Reinstall the ignition coil and secure with bolts.

3. Check and Replace Fuel Injector

• Tools Required: Fuel injector removal tool, multimeter
• Disconnect the fuel injector connector from cylinder 3.
• Test the injector’s resistance using a multimeter; compare the reading to manufacturer specifications.
• If the injector is faulty, remove it:
  1. Use the fuel injector removal tool to carefully pull the injector out of the rail.
  2. Install a new injector and ensure proper seating.
• Reconnect the injector connector.

4. Address Vacuum Leaks

• Visually inspect vacuum hoses and connections around cylinder 3 for signs of wear or damage.
• Replace any damaged hoses, ensuring a tight fit.

5. Compression Test (if needed)

• Tools Required: Compression tester
• Remove spark plugs from all cylinders for accurate testing.
• Insert the compression tester into cylinder 3 and crank the engine to get a reading.
• Compare the compression reading to the manufacturer’s specifications. If low, further investigation into engine internals may be required.