What causes the engine light to turn on in an Audi 80?

I recently bought a used Audi 80 and the engine light has been turning on sporadically. It doesn't seem to affect the car's performance, but I'm worried it may indicate a serious issue. Any ideas on why this might be happening?

The engine light could be turning on due to a faulty oxygen sensor. It's a common issue in older Audi 80 models and can be easily replaced.

Another possible cause could be a loose gas cap. Make sure it's tightened properly and see if the light turns off after a few drives.