Check and tighten the gas cap
Scan for diagnostic trouble codes with an OBD-II scanner
Repair the issue indicated by the code
Clear the codes with the scanner after repairs
Drive the vehicle to see if the light returns
Replace faulty spark plugs or ignition coils if needed
Fix vacuum leaks
Replace a bad oxygen sensor if needed
Repair or replace a failing mass airflow sensor if needed
Check and top off fluids if low
Inspect the catalytic converter if the code points to it
Replace a damaged battery or address charging issues if needed
Reset the light only after the underlying problem is fixed
Seek professional diagnosis if the light stays on or flashes