how to fix P0303 misfire 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 tools and parts needed.
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if necessary.
  2. Disconnect the ignition coil connector from the spark plug.
  3. Remove the ignition coil by unscrewing any retaining bolts and gently pulling it out of the spark plug well.
  4. Use a spark plug socket to remove the old spark plug from cylinder 3.
  5. Check the gap on the new spark plug to ensure it meets specifications (typically 0.030-0.035 inches for Ford V8 engines).
  6. Install the new spark plug, torque to manufacturer specifications (typically around 13 lb-ft).
  7. Reinstall the ignition coil and reconnect the connector.

3. Inspect and Replace Ignition Coil (if necessary)

• Sub-steps:
  1. If swapping the ignition coil revealed a fault, remove the faulty ignition coil from cylinder 3.
  2. Install the new ignition coil in the same position.
  3. Reconnect the ignition coil connector.

4. Check Fuel Injector (if necessary)

• Sub-steps:
  1. If the misfire persists, assess the fuel injector operation by testing the electrical connector and using a noid light.
  2. Remove and replace the fuel injector for cylinder 3 if it does not function properly.

5. Reassemble and Test

• Sub-steps:
  1. Reinstall any components removed during the diagnostic steps.
  2. Start the engine and monitor for smooth operation.
  3. Clear the DTC using the OBD-II scanner and take the vehicle for a test drive to ensure the issue is resolved.

Tools Required:

• OBD-II scanner
• Spark plug socket
• Torque wrench
• Ratchet and socket set
• Ignition coil puller (if necessary)

Parts Required:

• Spark plug for cylinder 3
• Ignition coil (if faulty)
• Fuel injector (if faulty)

Estimated Repair Time: 2-4 hours

Safety Warnings:

• Disconnect the battery before working on electrical components.
• Allow the engine to cool before performing repairs to avoid burns.