how to fix P0300 random misfire code on Toyota Tacoma N300 (2016-Present)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shocks.

2. Replace Spark Plugs

• Remove the engine cover (if applicable) using a socket set.
• Disconnect the ignition coil connectors and remove the coils using a socket set.
• Unscrew the spark plugs using a spark plug socket. Inspect old plugs for wear.
• Install new spark plugs, ensuring they are gapped correctly according to manufacturer specifications (typically around 0.044 inches for Tacoma).
• Reinstall the ignition coils and connect the electrical connectors.

3. Test and Replace Ignition Coils (if necessary)

• If ignition coils did not pass the resistance test, remove and replace them.
• Use a socket set to unbolt the faulty ignition coil.
• Install the new ignition coil and secure it with the bolts. Reconnect the electrical connector.

4. Inspect and Clean Fuel Injectors

• Remove the fuel rail by loosening the bolts and carefully pulling it away from the injectors.
• Inspect the injectors for clogs; if necessary, use a fuel injector cleaning kit to clean them.
• Reinstall the fuel rail and ensure seals are intact to prevent leaks.

5. Check for Vacuum Leaks

• Inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
• Use a smoke machine or carburetor cleaner to check for leaks while the engine is idling.
• Replace any damaged hoses or connectors found during inspection.

6. Perform a Compression Test

• Remove spark plugs again to access the cylinders.
• Insert a compression tester into each cylinder and crank the engine.
• Record the pressure readings; if any cylinder is significantly lower than others, further investigation is required (e.g., valve issues or head gasket failure).