how to fix P0303 code in Ford F-150 Fourteenth Generation (2021-present)

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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent any electrical issues.

2. Inspect and Replace Spark Plug

• Remove the engine cover (if applicable) using a socket set.
• Disconnect the ignition coil connector for cylinder 3.
• Remove the ignition coil using a socket set.
• Unscrew and remove the spark plug using a spark plug socket.
• Inspect the spark plug for signs of wear or damage (carbon fouling, excessive gap).
• Install a new spark plug (torque to manufacturer's specification, typically around 13 lb-ft).
• Reinstall the ignition coil and connector.

3. Check and Replace Ignition Coil

• If the spark plug is in good condition, test the ignition coil using a multimeter.
• Replace the ignition coil if it fails the resistance test (consult specifications for values).
• Reinstall the new ignition coil and reconnect the electrical connector.

4. Inspect Fuel Injector

• Remove the fuel rail (if necessary) to access the fuel injector for cylinder 3.
• Test the injector for proper operation using a noid light or by checking the resistance with a multimeter (consult specifications).
• Clean or replace the fuel injector if it is clogged or malfunctioning.

5. Compression Test

• If misfire persists, perform a compression test on cylinder 3.
• If compression is below specifications (typically around 130-200 psi depending on engine), further mechanical repair may be needed.