[sters2000]

Hi everyone, im new to the forum, i have a problem with my 2008 B200 cdi hope someone can help as it is stressing me out,start the car and it runs fine revs up fine no warning lights on i have also had it scanned and nothing shown up its all clear, now when driving it is a different matter get to around 1500-1700 rpm and it has a noise that i can only describe as exhaust blowing,missfire and induction noise all in one, i have a lot of mechanical knowledge but this has got me stumped,any advice would be greatly appreciated