What causes the check engine light to come on in my Audi A6?

I've noticed that the check engine light in my Audi A6 has been coming on frequently. Is this a common problem and what could be causing it?

There are a few potential causes for the check engine light to come on in your Audi A6. It could be something as simple as a loose gas cap, or it could be a more serious issue with the engine. It's best to get it checked out by a professional as soon as possible. In the meantime, you can try tightening the gas cap and see if that resolves the issue.