how to fix the check engine light in my Toyota Highlander Third Generation (2014-2019)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is turned off.
• Disconnect the negative battery terminal to prevent electrical shocks while working.

2. Address Diagnostic Codes

• Use the OBD-II scanner to retrieve and document error codes.
• Research the codes to determine the affected components.
• Clear the codes after repairs to reset the check engine light.

3. Repair Components

• Gas Cap Replacement (if applicable)

  • Remove the old gas cap.
  • Install a new gas cap that matches manufacturer specifications. Ensure it clicks securely.

• Replace Air Filter (if clogged)

  • Locate the air filter housing.
  • Unclip or unscrew the housing and remove the old air filter.
  • Install a new air filter, ensuring it fits snugly.

• Inspect and Replace Spark Plugs (if misfire is indicated)

  • Remove the ignition coil(s) if necessary.
  • Unscrew and remove old spark plugs.
  • Gap new spark plugs according to specifications and install them with a torque wrench (typically around 13 lb-ft).

• Repair or Replace Exhaust Components (if leaks are found)

  • Visually inspect exhaust manifold, catalytic converter, and muffler.
  • Replace any damaged components with OEM parts as needed.

4. Reconnect Battery and Test

• Reconnect the negative battery terminal.
• Start the engine and allow it to reach operating temperature.
• Monitor the dashboard for the check engine light and listen for any abnormal engine sounds.