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

Solution

1. Preparation

• Gather tools and ensure the vehicle is parked on a level surface.
• Disconnect the negative battery terminal to reset the system.
• Required tools: OBD-II scanner, socket set, screwdrivers, multimeter.

2. Address Fault Codes

• Use the OBD-II scanner to clear the stored fault codes.
• Note down the codes for reference.
• If codes indicate specific problems (e.g., P0420 for catalytic converter efficiency), proceed to focus on those areas.

3. Inspect and Repair Components

A. Gas Cap Inspection

• Remove the gas cap and inspect for cracks or damage.
• Replace gas cap if necessary. Ensure it clicks securely upon reinstallation.

B. Vacuum Leak Check

• Visually inspect all vacuum hoses for cracks or disconnections.
• Use a smoke machine to detect leaks if necessary. Repair or replace any damaged hoses.

C. Exhaust System Inspection

• Check the exhaust manifold and catalytic converter for visible damage.
• If a blockage is found, replace the affected component.

D. Ignition System Inspection

• Remove spark plugs and inspect for wear or fouling.
• Replace spark plugs and ignition coils as required.
• Torque spark plugs to manufacturer specifications (typically around 13 lb-ft).

E. Fuel System Check

• Connect a fuel pressure gauge to the fuel rail.
• Start the engine and check for adequate fuel pressure (typically around 40-50 PSI).
• Replace fuel filter or fuel pump if pressure is low.

4. Reassemble and Test

• Reconnect the battery terminal.
• Start the engine to see if the check engine light remains off.
• Test drive the vehicle under various conditions to ensure the issue is resolved.