how to fix P0303 misfire code in Ford F-150 14th Generation (2021-2024)

Learn how to diagnose and fix P0303 cylinder 3 misfire in Ford F-150 14th Generation. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Ensure the engine is cool before starting work.

2. Replace Spark Plug

• Sub-steps:
  1. Remove the ignition coil from cylinder 3 using a socket set.
  2. Disconnect the electrical connector from the ignition coil.
  3. Remove the spark plug using a spark plug socket.
  4. Inspect the old spark plug for signs of wear or fouling.
  5. Install a new spark plug (use OEM specifications, typically Motorcraft SP-534).
  6. Torque the spark plug to manufacturer specifications (typically around 13 lb-ft).
  7. Reinstall the ignition coil and reconnect the electrical connector.

3. Replace Ignition Coil

• Sub-steps:
  1. If the spark plug is fine, remove the ignition coil from cylinder 3 as previously done.
  2. Install a new ignition coil (OEM or equivalent).
  3. Ensure all electrical connections are secure.

4. Check and Replace Fuel Injector (if necessary)

• Sub-steps:
  1. Disconnect the fuel injector connector from cylinder 3.
  2. Remove the fuel rail to access the injector.
  3. Replace the fuel injector with a new one if it is clogged or malfunctioning.
  4. Reinstall the fuel rail and reconnect all components.

5. Perform Compression Test (if misfire persists)

• Sub-steps:
  1. Remove the spark plug from cylinder 3.
  2. Insert a compression gauge into the spark plug hole.
  3. Crank the engine and record the compression reading.
  4. Compare the reading with manufacturer specifications.
  5. If low, further investigation into potential mechanical issues is required.