how to fix P0303 code in my Toyota Highlander Third Generation (2014-2019)

Solution

1. Preparation

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

2. Replace Spark Plug

• Sub-steps:
  1. Locate and remove the engine cover (if applicable) using a socket set.
  2. Disconnect the ignition coil connector for cylinder 3.
  3. Remove the ignition coil by unbolting it and pulling it out.
  4. Unscrew the spark plug using a spark plug socket and ratchet.
  5. Inspect the old spark plug for wear or damage and compare it to manufacturer specifications.
  6. Install the new spark plug, torquing it to 13 lb-ft (17.5 Nm).
  7. Reinstall the ignition coil and reconnect the connector.

3. Replace Ignition Coil (if necessary)

• Sub-steps:
  1. If testing revealed a faulty ignition coil, remove the ignition coil as described above.
  2. Install the new ignition coil, ensuring it is seated properly.
  3. Reconnect the ignition coil connector securely.

4. Clean or Replace Fuel Injector (if necessary)

• Sub-steps:
  1. If the fuel injector is found to be clogged or defective, remove it by disconnecting the fuel rail.
  2. Clean the injector using a suitable fuel injector cleaner or replace it with a new one.
  3. Reinstall the fuel injector and ensure all connections are secure.