Engine start problem

[Andrei152610]

Hello. I have a Mercedes-Benz c200 2007 and I have a problem when I start the car because the engine is cold. I start it and for about 2-3 seconds it stays at 500 rpm, drops to 400 and then returns to 800. Do you know what the problem is?

 

[mioba]

prob a vac leak.
Codes read with live data will tell you.