my Toyota Corolla E210 (2019-2024) has a P0300 code, what does it indicate?

Solution

1. Preparation

• Gather tools: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, fuel pressure gauge, and cleaning supplies.
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Inspect and Replace Spark Plugs

• Sub-steps:
  1. Disconnect the negative battery terminal.
  2. Remove the engine cover (if applicable).
  3. Carefully disconnect the ignition coil connectors.
  4. Remove ignition coils using a socket set.
  5. Inspect and replace spark plugs if worn or fouled (use OEM recommended spark plugs).
  6. Reinstall ignition coils and reconnect the connectors.
  7. Reattach the engine cover.

3. Check and Replace Fuel Injectors

• Sub-steps:
  1. Remove the intake manifold if necessary to access fuel injectors.
  2. Disconnect fuel lines and electrical connectors from the injectors (use caution with fuel).
  3. Test each injector for proper operation using a multimeter.
  4. Replace any faulty injectors with OEM parts.
  5. Reassemble all components in reverse order, ensuring all connections are secure.

4. Perform Compression Test

• Sub-steps:
  1. Remove spark plugs to access the cylinders.
  2. Insert the compression tester into the spark plug hole.
  3. Crank the engine and note the compression readings.
  4. Compare readings across all cylinders to identify any abnormalities.
  5. If low compression is detected, further investigate potential causes (e.g., valve issues, head gasket failure).