my check engine light came on in my 2002 Subaru impreza sport

The car is computer is connected to a multitude of sensors for the engine & other components for the vehicle. It might be something as simple as low coolant in the cooling system or below normal oil level. Check everything u can, according to the Owner is Manual, & if its nothing obvious, u will have to locate a shop that can ''read'' the computer & tell u the problem. Nearly any auto shop has the equipment to find out why the check engine light is on.
Good luck.

Many auto parts stores have a code reader they will use for u for free. This plugs into ur car, & tells u what sensor is showing a problem.

Most of these readers can also ''clear'' the code, turning the light off.
Keep in mind though, that this does not fix the problem. You still either have a bad sensor or a mechanical failure.

Also, as long as the light as lit, u wo not pass an emissions inspection
The problem could then either be a defective sensor, or the sensor could be working & showing a real problem.

Basically, the light only comes on when the system senses a recurring or continuous fault. This keeps the light from coming on anytime the system sees a momentary fault.

Also, check ur gas cap. Believe it or not, on many cars, a loose cap can trigger a light.

Finally, if the light is blinking that is an indication the system has found a serious fault that needs immediate attention.

Is there a question you would like to ask?