Distronic buzz / chk engine light during test drive 2009 AMG S63. Forget it ?

What is your question?

Distronic buzzer on Check engine light on Thinking of a pre-purchase mechanic inspection Engine sounds OK...whooshing sound when revving which makes sense for 379 Cubic Inches with cold air intake tubes Anxious about laying out $22k on a car that NEEDS $22+K to get it on the road.

What makes this problem better or worse?

It's random and stays on

How long has your 2009 Mercedes-Benz S63 AMG had this problem?

a month