how to deal with the P0304 code in my Ford F-150 12th Generation (2009-2014)

Learn to diagnose and fix P0304 cylinder 4 misfire in Ford F-150 12th Generation. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before beginning work.

2. Replace Spark Plug

• Remove the engine cover if applicable.
• Use a socket and ratchet to remove the spark plug from cylinder 4.
• Inspect the removed spark plug for wear; replace with a new one if necessary.
• Torque the new spark plug to manufacturer specifications (typically around 13-15 lb-ft).

3. Replace Ignition Coil

• Disconnect the electrical connector from the ignition coil for cylinder 4.
• Remove the bolt securing the ignition coil using a socket and ratchet.
• Pull the ignition coil straight out to avoid damaging it.
• Install the new ignition coil and secure it with the bolt.
• Reconnect the electrical connector.

4. Inspect and Clean Fuel Injector

• Disconnect the fuel injector connector for cylinder 4.
• Remove the fuel rail if necessary to access the injector.
• Clean the injector or replace it if clogged or malfunctioning.
• Reassemble the fuel rail and reconnect the injector.

5. Check Compression

• Remove the spark plug from cylinder 4.
• Insert a compression gauge into the spark plug hole.
• Crank the engine a few times to get a reading.
• Compare the reading to manufacturer specifications (typically around 100-150 psi).