leaking injector puffing sound
 

hello

i am new to the mercedes forum, i have purchased a mercedes a170 cdi avantgarde 2001 model. there seems to be a leaking injector , and its putting diesel fumes into the car , there is a puffing noise , i would like to know if its an easy fix , new seal etc , and how do i get at the injectors, how do i remome the airbox unit ?

kind regards
davy pagan