A solid check engine light means the car's computer logged a fault but the issue isn't catastrophic. A flashing light means an active misfire — drive easy and get it scanned today; continuing can damage the catalytic converter.
The most common causes we see: loose gas cap, worn spark plugs, failing oxygen sensor, EVAP system leaks, and bad ignition coils. A proper diagnosis costs $80–$160 and tells you exactly what's wrong instead of guessing.