how to fix P0300 code in Ram 1500 DT (2019-Present)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before beginning the repair.

2. Inspect and Replace Spark Plugs

• Remove the ignition coil cover (if applicable) using a socket set.
• Carefully remove the ignition coils and set them aside.
• Use a spark plug socket to remove the spark plugs.
• Inspect the spark plugs for wear and replace them with OEM or equivalent parts if needed.
  • Torque Specification: Tighten new spark plugs to manufacturer’s specified torque (typically around 13-15 lb-ft).
• Reinstall the ignition coils and connect the wiring harness.

3. Check and Replace Ignition Coils

• If spark plugs are in good condition, test each ignition coil with a multimeter:
  • Set the multimeter to ohms and check the primary and secondary resistance.
  • Replace any coils that do not meet specifications.
• Reinstall any replaced ignition coils and ensure they are properly secured.

4. Inspect and Clean Fuel Injectors

• If misfires persist, remove the fuel rail (ensure fuel pressure is relieved prior).
• Inspect fuel injectors for clogs or leaks.
• Use an injector cleaner or replace faulty injectors as necessary.
• Reinstall the fuel rail with new O-rings and reconnect all lines.

5. Vacuum Leak Inspection

• Perform a visual inspection of all vacuum hoses and connections.
• Replace any damaged hoses.
• If needed, use a smoke test to find hidden leaks.

6. Compression Test

• If issues continue, perform a compression test on each cylinder.
• Replace or repair any cylinder with significantly lower compression than others.