how to fix the P0303 code in my Ram 1500 DT (2019-Present)

Learn how to diagnose and fix P0303 cylinder 3 misfire in Ram 1500 DT. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to ensure safety.

2. Inspect and Replace Spark Plug

• Remove the engine cover if applicable.
• Using a spark plug socket and ratchet, remove the spark plug from cylinder 3.
• Inspect the spark plug for signs of fouling or damage (e.g., carbon buildup, wear).
• If necessary, replace the spark plug with a new one, ensuring it is gapped according to the manufacturer’s specifications (typically around 0.040 inches).
• Reinstall the spark plug, tightening it to the recommended torque specification (usually around 13 lb-ft).

3. Inspect and Replace Ignition Coil

• Disconnect the wiring harness from the ignition coil on cylinder 3.
• Remove the ignition coil using a socket and ratchet.
• Inspect the ignition coil for cracks or signs of electrical failure.
• If defective, replace it with a new ignition coil, ensuring the connector is securely attached.

4. Inspect and Replace Fuel Injector

• Disconnect the fuel injector connector for cylinder 3.
• Remove the fuel rail if necessary to access the injector.
• Replace the fuel injector for cylinder 3 if it is found to be faulty. Use new O-rings for a proper seal.
• Reinstall the fuel rail and reconnect the injector connector.

5. Reassemble and Test

• Reconnect the negative battery terminal.
• Start the engine to ensure it runs smoothly and check that the check engine light is no longer illuminated.
• Conduct a test drive to confirm the repair and monitor for any returning symptoms.