My service engine soon light just came on in my 1999 0lds alero does this mean car will break down?

Not necessarily. The service engine soon light is designed to alert you to a potential problem with your vehicle's engine or emissions system. It does not necessarily mean that your car will break down, but it is important to have the issue diagnosed and repaired as soon as possible to prevent any further damage.

When the service engine soon light comes on, it is recommended that you take your vehicle to a qualified mechanic or automotive repair shop to have the issue diagnosed. The mechanic will be able to use a diagnostic tool to read the trouble codes that have been stored in the vehicle's computer. These codes will provide information about the nature of the problem, and the mechanic will be able to recommend the appropriate repairs.

In some cases, the service engine soon light may come on due to a minor issue, such as a loose gas cap or a faulty sensor. In other cases, it may indicate a more serious problem, such as an engine misfire or a transmission problem. It is important to have the issue diagnosed as soon as possible to prevent any further damage and to ensure the safety of your vehicle.