How to troubleshoot a check engine light on an Audi A4?

I recently bought an Audi A4 and the check engine light keeps turning on. I'm not sure what the problem could be. Can anyone offer some advice on how to troubleshoot this issue?

First, make sure your gas cap is tightly sealed. A loose gas cap is a common cause for the check engine light to turn on. If that's not the issue, it would be best to take your car to an authorized Audi dealer for a diagnostic test. They have the necessary equipment to accurately diagnose any potential problems.

There could be a number of reasons why the check engine light is on. It's always a good idea to check your engine oil level and make sure it's at the recommended level. If that's not the issue, you may need to replace the oxygen sensor or the catalytic converter. I recommend taking your car to a trusted mechanic for further diagnosis.

I had a similar issue with my Audi A4 and it turned out to be a faulty mass airflow sensor. If you notice any decrease in engine performance or unusual noises, it could be a sign of a faulty sensor. I suggest taking your car to a certified technician to get it checked out.