Hi all quick question , my 2010 diesel outback has developed a leak from passenger side rear . According to mechanic it is coming from a secondary filter ?? He said it has never been serviced so it is failing,  Ive never heard of a car having 2 fuel filters , if it is leaking can anyone point me in the direction of the part number so i could get hold a one to replace it. 
 
	Many thanks !!
 
	Graham