how to fix P0305 misfire code on Ford F-150 13th Generation (2015-2020)

Learn how to diagnose and fix P0305 cylinder 5 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 battery to ensure safety while working on electrical components.

2. Inspect and Replace Spark Plug

• Sub-steps:
  • Remove the engine cover (if applicable) using a socket set.
  • Disconnect the ignition coil connector for cylinder 5.
  • Remove the ignition coil bolt with a socket and pull out the coil.
  • Remove the spark plug using a spark plug socket and inspect it for wear or fouling.
  • Replace the spark plug with a new one, ensuring it is gapped to manufacturer specifications (typically around 0.050 inches for F-150).
  • Reinstall the ignition coil and connect the electrical connector.

3. Inspect and Replace Ignition Coil

• Sub-steps:
  • If the spark plug is in good condition, test the ignition coil's resistance using a multimeter.
  • If the coil is faulty, remove it as described above.
  • Replace it with a new ignition coil designed for the F-150.
  • Reconnect the ignition coil connector and ensure it is securely fastened.

4. Inspect and Replace Fuel Injector

• Sub-steps:
  • If the misfire persists, check the fuel injector operation.
  • Remove the intake manifold (if necessary) to access the fuel injector for cylinder 5.
  • Disconnect the fuel injector electrical connector and fuel line (be cautious of fuel spray).
  • Remove the fuel injector and inspect it for clogs or damage.
  • Replace the injector if it is faulty, using new O-rings.
  • Reinstall the fuel line and electrical connector.

5. Final Assembly and Testing

• Sub-steps:
  • Reinstall any components removed during the repair (e.g., intake manifold, engine cover).
  • Reconnect the battery.
  • Start the engine and allow it to idle.
  • Monitor for any check engine light and ensure smooth engine operation.