what does a P0303 code mean for my Ford F-150

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 necessary tools and parts.
• Disconnect the battery before starting work on electrical components.
• Ensure the engine is cool before beginning repairs.

2. Replace Spark Plug and Ignition Coil

• Remove the engine cover if necessary.
• Disconnect the electrical connector from the ignition coil on cylinder 3.
• Unbolt and remove the ignition coil.
• Remove the spark plug using a spark plug socket and ratchet.
• Inspect the old spark plug for wear; replace it with a new one if necessary.
• Install the new spark plug and torque it to the manufacturer’s specifications (typically around 13-15 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Test Fuel Injector

• Disconnect the fuel injector connector from cylinder 3.
• Use a multimeter to check the resistance of the fuel injector (should typically be around 12-16 ohms).
• If the injector is faulty, remove it and replace it with a new one.
• Reconnect the fuel injector connector.

4. Conduct Compression Test

• Remove spark plugs from cylinder 3 and adjacent cylinders for ease of access.
• Insert the compression tester into the spark plug hole of cylinder 3.
• Crank the engine to get a reading; compare it with manufacturer specifications (usually around 100-150 psi).
• If readings are low, further investigation into the engine’s internal components may be needed.