my Toyota Camry XV50 (2012-2017) has a check engine light code P0300, what should I do

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, fuel pressure gauge, multimeter, compression tester.
• Disconnect the negative battery terminal to ensure safety during repairs.

2. Inspect and Replace Spark Plugs

• Remove the ignition coils by unscrewing the bolts and disconnecting the electrical connectors.
• Remove the spark plugs using a spark plug socket.
• Inspect the spark plugs for wear (e.g., carbon buildup, erosion).
• Replace with new spark plugs that meet OEM specifications (typically NGK or Denso).
• Torque the new spark plugs to the manufacturer's specifications (usually around 13-15 lb-ft).

3. Check and Replace Ignition Coils (if necessary)

• If any spark plugs were found faulty, check the corresponding ignition coils.
• Test each ignition coil with a multimeter to ensure proper resistance (consult service manual for specifics).
• Replace any faulty ignition coils with OEM parts.

4. Fuel System Inspection

• Attach the fuel pressure gauge to the fuel rail's test port.
• Turn the ignition to the "ON" position (do not start) to check fuel pressure.
• Compare the reading to the manufacturer's specifications (typically 40-50 psi).
• If pressure is low, check the fuel pump and fuel filter; replace as needed.

5. Compression Test

• Remove the ignition coils and spark plugs.
• Insert the compression tester into each cylinder's spark plug hole.
• Crank the engine for a few seconds and record the pressure reading.
• Compare readings across all cylinders; a significant difference may indicate internal engine issues.