how to fix P0300 random misfire code in my Toyota Camry?

Solution

1. Preparation

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

2. Inspect and Replace Spark Plugs

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coils by unscrewing the mounting bolts and disconnecting the electrical connectors.
• Remove the old spark plugs using a spark plug socket.
• Inspect the spark plugs for wear; if they show signs of damage or excessive carbon buildup, replace with OEM or equivalent spark plugs.
• Install new spark plugs, ensuring to torque them to the manufacturer’s specifications (typically around 13-15 ft-lbs for most Toyota models).

3. Check and Replace Ignition Coils (if necessary)

• Inspect ignition coils for cracks or signs of overheating.
• If any coils appear damaged, replace them. Disconnect the electrical connector and unscrew the coil from the cylinder head.
• Install the new ignition coil and reconnect the electrical connector.

4. Fuel System Inspection

• Tools Required: Fuel pressure gauge.
• Connect the fuel pressure gauge to the fuel rail test port.
• Turn the ignition key to the "ON" position (do not start the engine) to check the fuel pressure. It should match the manufacturer’s specifications (typically around 30-40 psi for a Camry).
• If pressure is inadequate, inspect the fuel filter and fuel pump; replace them if necessary.

5. Vacuum Leak Inspection

• Visually inspect all vacuum hoses for cracks or disconnections.
• If a leak is suspected, use a smoke machine or carburetor cleaner to detect leaks while the engine is running.