how to fix P0303 cylinder 3 misfire in Ford F-150 14th Generation (2021-2024)

Learn how to diagnose and fix P0303 cylinder 3 misfire in Ford F-150 (2021-2024). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

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

2. Spark Plug and Ignition Coil Replacement

1. Remove the engine cover (if applicable) using a socket set.
2. Disconnect the electrical connector from the ignition coil on cylinder 3.
3. Remove the ignition coil mounting bolts and pull out the ignition coil.
4. Remove the spark plug using a spark plug socket. Inspect for wear or fouling.
5. Replace the spark plug with a new one, ensuring proper gap (refer to manufacturer specifications).
6. Install the new ignition coil onto the spark plug and secure it with the mounting bolts.
7. Reconnect the electrical connector to the ignition coil.

3. Fuel Injector Inspection/Replacement (if necessary)

1. If the fuel injector is suspected to be faulty, disconnect the fuel line using a fuel line disconnect tool (be cautious of fuel spillage).
2. Remove the fuel injector connector and mounting clip.
3. Pull out the fuel injector from its rail.
4. Inspect the injector for clogs or damage. Replace it with a new injector if necessary.
5. Reinstall the new or cleaned fuel injector, ensuring it seats properly.
6. Reconnect the fuel line and electrical connector.

4. Final Assembly

1. Reinstall the engine cover (if removed).
2. Reconnect the negative battery terminal.
3. Clear the error codes using the OBD-II scanner.