how to diagnose P0300 misfire code on Tesla Model S Plaid/Refresh (2021-present)

Learn how to diagnose and fix P0300 engine misfire in Tesla Model S Plaid. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the vehicle's high-voltage battery according to Tesla's safety procedures to prevent electrical shock.
• Ensure the vehicle is in a safe and ventilated area.

2. Replace Spark Plugs

• Remove Engine Cover: Unscrew and remove the engine cover to access the spark plugs.
• Disconnect Ignition Coils: Unplug the electrical connectors from the ignition coils.
• Remove Spark Plugs: Use a spark plug socket and ratchet to carefully unscrew and remove the spark plugs.
• Install New Spark Plugs: Apply anti-seize compound on the threads of the new spark plugs, then install them hand-tight, followed by torqueing to the manufacturer’s specified value (typically 18-20 lb-ft).

3. Replace Ignition Coils (if necessary)

• Remove Old Ignition Coils: Unscrew and remove the ignition coils from the spark plug wells.
• Install New Ignition Coils: Place the new ignition coils into their respective locations, ensuring they seat properly.
• Reconnect Electrical Connectors: Plug in the electrical connectors to the new ignition coils.

4. Check Fuel System

• Inspect Fuel Injectors: If fuel pressure is low, check fuel injectors for clogs or leaks. Clean or replace if necessary.
• Replace Fuel Filter: If applicable, replace the fuel filter to ensure proper fuel flow.

5. Reassemble and Test

• Reattach the engine cover.
• Reconnect the high-voltage battery.
• Start the vehicle and monitor for any check engine lights or unusual behavior.