my Ford F-150 14th Generation (2021-2024) has a check engine light with code P0301

Solution

1. Preparation

• Gather tools: OBD-II scanner, socket set, torque wrench, compression tester, multimeter, and basic hand tools.
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Inspect Spark Plug and Ignition Coil

• Remove the engine cover (if applicable) using a socket set.
• Disconnect the ignition coil connector for cylinder 1.
• Unbolt the ignition coil using the socket set and remove it.
• Inspect the spark plug for wear, carbon buildup, or damage.
• Replace the spark plug if worn; use the manufacturer's specified gap.
• Reinstall the ignition coil and reconnect the connector securely.

3. Check for Vacuum Leaks

• Visually inspect vacuum hoses for cracks or disconnections.
• Use a smoke machine or carburetor cleaner to identify leaks around the intake manifold and throttle body.
• Repair or replace any damaged hoses or gaskets.

4. Perform Compression Test

• Remove the spark plug from cylinder 1.
• Insert the compression tester into the spark plug hole.
• Crank the engine for several seconds and record the compression reading.
• Compare the reading to the manufacturer's specifications; replace the cylinder head gasket or piston rings if below specifications.

5. Test Fuel Injector

• Disconnect the fuel injector connector for cylinder 1.
• Use a multimeter to test the injector for resistance; refer to service manual for specifications.
• If the injector is faulty, replace it by removing the fuel rail and installing a new injector.

6. Reassemble and Clear Codes

• Reinstall all components in reverse order, ensuring all bolts are torqued to specifications.
• Reconnect the battery if it was disconnected.
• Use the OBD-II scanner to clear the check engine light and codes.