Here's why:
* Variety of potential issues: The light is a general warning, not a specific diagnosis. The problem could be something minor (loose gas cap) or something major (catalytic converter failure, serious engine problem).
* Progressive damage: Some problems will get worse if ignored. For example, a failing oxygen sensor might initially just cause slightly reduced fuel efficiency, but prolonged use could lead to damage to the catalytic converter, which is a very expensive repair. A leaking coolant sensor might eventually lead to engine overheating and catastrophic engine failure.
* Safety concerns: Some issues could affect your car's drivability, braking, or steering, creating a safety hazard.
What to do:
1. Get the code read: You need to find out *why* the light is on. This requires getting the diagnostic trouble codes (DTCs) read. You can do this in several ways:
* Auto parts store: Most auto parts stores (like AutoZone, Advance Auto Parts, etc.) offer free check engine light diagnostics. They'll plug a scanner into your car's OBD-II port and read the codes. They can then give you a general idea of what the problem might be.
* OBD-II scanner: You can buy a relatively inexpensive OBD-II scanner for your own use. These plug into your car's OBD-II port (usually located under the dashboard) and display the trouble codes. Many apps work with Bluetooth OBD-II scanners and give you more information.
* Mechanic: A mechanic will have the tools and expertise to read the codes and diagnose the problem. This is the most reliable option, especially if you're not mechanically inclined.
2. Address the problem: Once you know the code(s), you can research the potential causes online or consult a mechanic. Some minor issues you might be able to fix yourself (like tightening a loose gas cap), but more complex problems will require professional attention.
3. Don't delay: The longer you wait, the more likely the problem is to worsen and become more expensive to fix.
In short: Driving with the check engine light on carries risks. Get the code read as soon as possible and address the underlying problem to prevent further damage and potential safety hazards. For a 1999 vehicle, regular maintenance is crucial, so don't dismiss this warning.
