What are the common causes of check engine light appearing on a Vauxhall Astra?

I own a Vauxhall Astra and recently the check engine light appeared on my dashboard. I'm not sure what could be causing this and I'm worried it could be a serious issue. Can someone help me understand the possible causes and what actions I should take?

The most common cause of the check engine light on a Vauxhall Astra is a faulty oxygen sensor. This can be easily replaced by a mechanic and should be done as soon as possible to avoid any further engine damage.

Another possible cause of the check engine light is a loose or faulty gas cap. This is an easy fix and you can try tightening the gas cap first before taking your car to a mechanic.

A damaged catalytic converter can also trigger the check engine light. This is a more serious issue and requires immediate attention from a mechanic.