what causes the P0300 code on my Toyota Camry XV70 (2018-2024)

Solution

1. Preparation

• Tools Required: OBD-II scanner, spark plug socket, multimeter, compression tester, fuel pressure gauge, basic hand tools.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal for safety.

2. Inspect Spark Plugs

• Remove the spark plug wires or ignition coil connectors.
• Use a spark plug socket to remove each spark plug.
• Inspect each spark plug for wear, carbon buildup, or damage. Replace if necessary.
• Check the spark plug gap with a feeler gauge and adjust or replace as needed.

3. Test Ignition Coils

• Reconnect the ignition coils and use a multimeter to test the primary resistance (refer to service manual for specific values).
• If any coils are out of specification, replace the faulty ignition coil.

4. Check Fuel Injectors

• Connect a fuel pressure gauge to the fuel rail.
• Turn the ignition on (do not start) and check the fuel pressure. It should match the manufacturer’s specification.
• If pressure is low, inspect the fuel pump and filter. Replace as necessary.
• Use a noid light to test the injector pulse. Replace any non-functioning injectors.

5. Inspect Vacuum Hoses

• Visually inspect all vacuum hoses for cracks, breaks, or loose connections.
• Use a smoke test if necessary to identify hidden leaks.
• Replace any damaged hoses.

6. Perform Compression Test

• Remove all spark plugs and attach the compression tester to the first cylinder.
• Crank the engine and record the compression reading.
• Repeat for all cylinders, ensuring that the readings are within specifications.
• If any cylinder shows low compression, further investigation may be necessary (valve, piston rings, etc.).