2005 Mercedes-Benz C230 Q&A

2005 Mercedes-Benz C230 Question: Lately my car has been revving itself up and down when I 1st turn it on.

The RPM goes up and down roughly between 30-40 rpms until I start driving it This happens in the morning and goes away as soon as I begin to drive...Does something need to be replaced? -
Answer 1
is the check engine light on , did you pull the air cleaner off ? sounds like a vacuum leak ,i could be wrong , -