how to fix P0300 code in Toyota Corolla E210 (2019-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative terminal of the battery to ensure safety.
• Allow the engine to cool down before starting work.

2. Inspect and Replace Ignition Components

• Tools Required: Socket set, torque wrench, spark plug socket
• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Remove the ignition coils by unscrewing the retaining bolts and disconnecting the electrical connectors.
  3. Inspect the spark plugs for wear or fouling; replace them if necessary (recommended gap: 0.043 inches).
  4. Reinstall new or cleaned ignition coils and secure them with bolts.
  5. Reconnect the electrical connectors to the ignition coils.

3. Check and Replace Fuel Components

• Tools Required: Fuel pressure gauge, socket set
• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail.
  2. Turn on the ignition (do not start the engine) and check the fuel pressure (should be within manufacturer specifications).
  3. If pressure is low, check the fuel pump and replace if necessary.
  4. Inspect the fuel filter and replace if clogged.

4. Inspect and Repair Air Intake System

• Tools Required: Screwdriver set, vacuum gauge
• Sub-steps:
  1. Check the air filter; replace if dirty.
  2. Inspect the intake manifold for leaks using a vacuum gauge.
  3. Replace any damaged vacuum hoses and reassemble the intake system.

5. Verify Compression

• Tools Required: Compression tester
• Sub-steps:
  1. Remove the spark plugs.
  2. Insert the compression tester into each cylinder and crank the engine.
  3. Record the compression readings; they should be within manufacturer specifications.
  4. If any cylinder shows low compression, further investigation is needed for potential internal engine problems.