I have searched the threads and cannot find anything about a pre fuel filter on my 2007 5.9. I found the thread for the second gen and the pre filter on them and how to replace. If I have one are they the same part numbers as the second gen? I have 18k on mine now and have changed the primary filter three times. The first change was very very nasty, and I am wondering what the pre filter would look like if I have one. I am not really exp any performance issues and my hand overall hand calculated milage is 18.27 for 2007. I have tracked every fill up on gasbuddy.com since I bought the truck and all of the maintenance that I have done. Thanks in advance. Bill

 

As far as I know there is no pre fuel filter on your engine. Your filter will be black in color but if its real bad then I would say the place you buy fuel at may have a problem with dirty tanks. If its a black slime on your filter you could have algae growing in your tank and will need to use and additive to kill it.