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

Solution

1. Preparation

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

2. Inspect and Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench, dielectric grease.
• Remove the ignition coil from cylinder 3.
• Unscrew and remove the spark plug from cylinder 3.
• Inspect the spark plug for signs of wear or damage (fouling, excessive wear).
• If necessary, replace the spark plug with a new one, ensuring it matches OEM specifications.
• Apply dielectric grease to the spark plug boot before reinstallation.

3. Inspect and Replace Ignition Coil

• Tools Required: Socket set, ratchet.
• Remove the ignition coil from cylinder 3 after spark plug replacement.
• Inspect the ignition coil for cracks or damage.
• If defective, replace it with a new ignition coil that meets OEM specifications.
• Reinstall the ignition coil securely.

4. Check and Clean Fuel Injector

• Tools Required: Fuel injector cleaner, injector removal tool (if replacement is necessary).
• If the injector is suspected to be clogged, remove it from cylinder 3.
• Clean the injector using a fuel injector cleaning kit or replace it if it does not spray correctly.
• Reinstall the fuel injector securely.

5. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0303 code and other related codes.