i also have an 06 but it has 43,000 and about a week ago i had the cp3 replaced under warranty and now it has a sort of knock could it be the same issue?? but the thing is i am not getting any codes and if the lift pump is bad it should throw a code?? my knock you can hear dead in front of the motor more at idle but, my fuel millage isnt down the lie o meter is saying im averaging 14.6 but, i do have 4 inches of lift in the front and 1 1.5 in the rear with 37s so i dont think the millage is horrible?? thanks guys