How to troubleshoot Audi 80 "Check Engine" Light issue?

My Audi 80's check engine light keeps turning on, even though I recently had it serviced. I'm worried that there may be a more serious problem. Any suggestions on how to troubleshoot this issue?

First, check the gas cap. A loose or faulty gas cap is a common cause of a check engine light. If that's not the issue, try resetting the light by disconnecting the car's battery for a few minutes and then reconnecting it. If the light still comes on, it may be a faulty oxygen sensor.

Have you noticed any other symptoms, such as odd noises or difficulty starting the car? Those could indicate a more serious problem. It's best to take your car to a mechanic to get a diagnostic check and see what the issue may be.