what causes the check engine light to come on in my Toyota Tacoma N300 (2016-Present)

Solution

1. Preparation

• Gather tools and parts necessary for the repair.
• Ensure the vehicle is parked on a flat surface, and the engine is off.
• Disconnect the negative battery terminal to reset the engine control module (ECM).

2. Address Error Codes

• Using the OBD-II scanner, note down any error codes present.
• Research and troubleshoot based on the specific codes (e.g., P0420 for catalytic converter efficiency).

3. Inspect and Replace Components

A. Gas Cap

• Check for cracks or damage; if defective, replace with a new gas cap.

B. Ignition Components

• Remove the spark plugs using a socket set. Inspect for wear; replace if necessary.
• Test ignition coils with a multimeter. Replace any faulty coils.

C. Air Intake System

• Remove the air intake hose and inspect for cracks or loose fittings.
• Clean the air filter, or replace if dirty.

D. Exhaust System

• Visually inspect the exhaust system for leaks. Use exhaust leak detection spray if needed.
• Replace any damaged gaskets or components in the exhaust system.

4. Reset Check Engine Light

• Reconnect the negative battery terminal.
• Start the engine and allow it to idle for a few minutes to reset the ECM.
• Use the OBD-II scanner to clear any stored error codes.