how to fix P0303 code in my Ford F-150 12th Generation (2009-2014)

Learn how to diagnose and fix P0303 cylinder 3 misfire in Ford F-150 (2009-2014). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shocks.
• Allow the engine to cool down before starting work.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 3 using a socket set.
• Inspect the spark plug for wear or fouling; if damaged, replace it with a new spark plug (use OEM specifications).
• Torque the new spark plug to manufacturer specifications (typically around 13 lb-ft).
• Reinstall the ignition coil.

3. Test and Replace Ignition Coil (if necessary)

• If the spark plug is in good condition, test the ignition coil's resistance with a multimeter (consult vehicle specifications for resistance values).
• If the coil is faulty, remove it, and replace it with a new one, ensuring it is compatible with the F-150.
• Reconnect the ignition coil wiring and ensure connections are secure.

4. Check and Replace Fuel Injector (if necessary)

• Use a noid light to verify that the fuel injector for cylinder 3 is receiving a signal.
• If the fuel injector is not functioning, remove it from the engine by disconnecting the fuel line and electrical connector.
• Replace the faulty fuel injector with a new one, ensuring proper alignment and securing the connections.

5. Final Assembly

• Reconnect any components that were removed for access.
• Reconnect the negative battery terminal.
• Start the engine and allow it to idle.