My stock 04 Duramax LB7 is at 20k and seems to have some loss of power from the last time I pulled with it. It happened or at least I noticed it after the last time I had it at the dealer. The power loss is not a lot but it is there. I have been hearing rumers about the new Fords being "detuned" by the dealers when brought in for service unkown to the owners. This seems like a strech even for Ford owners... http://www.dieselplace.com/forum/smileys/Big Smile.gif Any ideas what might be the problem with mine?

What was it at the dealer for?

I would check the fuel filter. Especially if you have never changed it.