how to fix P0303 misfire code on Ford F-150 13th Generation (2015-2020)

Learn how to diagnose and fix P0303 cylinder 3 misfire in Ford F-150 (2015-2020). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool before starting work.

2. Inspect and Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Remove the ignition coil from cylinder 3 by unscrewing the mounting bolts.
• Carefully pull the spark plug wire/connector off the ignition coil.
• Remove the spark plug using the spark plug socket.
• Inspect the spark plug for wear or fouling; replace with a new one if necessary.
• Torque the new spark plug to manufacturer specifications (typically around 13-15 lb-ft).

3. Check and Replace Ignition Coil

• Inspect the ignition coil for cracks or damage.
• If faulty, remove the ignition coil by unscrewing it from the engine.
• Connect the new ignition coil, ensuring a secure fit.
• Reconnect the spark plug wire/connector.

4. Inspect and Replace Fuel Injector

• Tools Required: Fuel injector removal tool, container for fuel spillage.
• Disconnect the fuel line and electrical connector from the fuel injector.
• Remove the fuel injector by pulling it out of the intake manifold.
• Install the new fuel injector, ensuring it seats correctly.
• Reconnect the fuel line and electrical connector securely.

5. Final Checks

• Reconnect the negative battery terminal.
• Start the engine and allow it to idle.
• Check for any leaks and ensure the engine runs smoothly.