how to fix the P0304 misfire code on my Ford F-150 13th Generation (2015-2020)

Learn how to diagnose and fix P0304 cylinder 4 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 ensure safety.

2. Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench, gap tool
• Remove the ignition coil from cylinder 4.
• Unscrew and remove the spark plug.
• Inspect the spark plug for wear and gap; replace if necessary.
• Install a new spark plug, ensuring proper gap (typically 0.030 inches for Ford engines).
• Torque the spark plug to the manufacturer’s specification (usually around 13 lb-ft).

3. Inspect/Replace Ignition Coil

• Tools Required: Socket set, ratchet
• Visually inspect the ignition coil for cracks or damage.
• If faulty, remove the ignition coil and replace it with a new unit.
• Reinstall the ignition coil and ensure it is seated properly.

4. Check Fuel Injector

• Tools Required: Noid light or multimeter
• Disconnect the fuel injector connector for cylinder 4.
• Connect a noid light to verify the injector is receiving the proper signal.
• If the noid light does not illuminate, inspect wiring and ECM connections.
• If the injector is faulty, replace it with a new one.

5. Reassemble and Test

• Reconnect the battery terminal.
• Start the engine and allow it to reach operating temperature.
• Monitor for any codes or misfire symptoms during idle and light acceleration.