why does my Honda Civic 10th Generation (2016-2021) check engine light keep coming on

Solution

1. Preparation

• Gather tools: OBD-II scanner, socket set, torque wrench, multimeter, fuel pressure gauge.
• Ensure the vehicle is parked on a level surface and the engine is off. Disconnect the battery negative terminal for safety.

2. Address Fault Codes

• Connect the OBD-II scanner to the vehicle's diagnostic port.
• Retrieve and document any trouble codes.
• Research the trouble codes to determine the appropriate repairs needed (e.g., P0420 for catalytic converter efficiency).

3. Inspect and Repair Components

• Gas Cap Check

  • Remove the gas cap and inspect for cracks or wear.
  • If faulty, replace with a new gas cap and ensure it clicks securely when tightened.

• Ignition System Inspection

  • Remove spark plugs using a socket set. Inspect for wear, carbon buildup, or damage.
  • Replace spark plugs if necessary and torque to manufacturer specifications (typically around 13-16 ft-lbs).
  • Check ignition coils for proper function using a multimeter.

• Fuel System Check

  • Connect the fuel pressure gauge to the fuel rail.
  • Turn the ignition to the "ON" position (do not start the engine) and check the pressure reading against manufacturer specifications.
  • Replace the fuel pump or filter if pressure is outside of the normal range.

4. Reset the Check Engine Light

• After completing repairs, reconnect the battery negative terminal.
• Use the OBD-II scanner to clear any stored trouble codes.
• Start the engine and observe if the check engine light remains off.