I just installed the Fuel Pak on my 09 FLHT and what a difference, not to mention it got rid of the Pinging. The only prob I have with it is when you plug the fuel pak in you can't secure the computer back in to the bracket under the seat beacuse it's too long so it's jammed half way in the bracket. Othere than that it's awesome.

 

I too had problems getting the Fuel Pak and the ECM back into the correct spot on my Ultra. With some work, I was finally able to get them seated into the top of the battery cover. Not sure about the 09's, but it will go on the 08 with a little wiggling and pressure.