how to fix P0303 code on 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 necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool down before starting work.

2. Inspect Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the engine cover if applicable.
• Locate the spark plug for cylinder 3.
• Remove the spark plug using the spark plug socket.
• Inspect the spark plug for signs of wear or fouling (e.g., oil, carbon buildup).
• If damaged, replace with a new spark plug, ensuring to torque it to the manufacturer’s specifications (typically around 13-15 lb-ft).

3. Check Ignition Coil

• Tools Required: Socket set, multimeter.
• Disconnect the electrical connector from the ignition coil of cylinder 3.
• Remove the ignition coil using the appropriate socket.
• Use a multimeter to test the primary and secondary resistance of the coil.
• If the ignition coil is faulty, replace it with a new one.

4. Inspect Fuel Injector

• Tools Required: Fuel injector removal tool, multimeter.
• Disconnect the fuel injector connector for cylinder 3.
• Remove the fuel injector using the injector removal tool.
• Test the injector resistance using a multimeter; it should match specifications (typically around 12-16 ohms).
• If the injector is faulty, replace it with a new one.

5. Perform Compression Test

• Tools Required: Compression tester.
• Remove the spark plug for cylinder 3.
• Insert the compression tester into the spark plug hole.
• Crank the engine and record the compression reading.
• Compare the reading with manufacturer specifications; if low, further diagnosis is required for potential internal engine issues.

6. Reassemble and Test

• Reinstall the spark plug, ignition coil, and fuel injector as necessary.
• Reconnect the negative battery terminal.
• Start the engine and observe for any check engine light illumination or rough idling.