Just thought I would pass this on ... I installed qa fuel pressure gauge on my '06 2500 CTD a while back. I have been changing the fuel filter approx every 10K miles. I notice the fuel pressure starts to drop off around then as well, from 8 psi to 6 and then 4 psi. I normally order filers from Geno's Garage. I was out and stopped at my local Carquest store and picked one up there and installed it. My fuel gauge began acting erratically, dropping from 8 psi to 0 to 2 psi and bouncing around. Sometimes indicating 0 psi for quite a while. I thought I must have a loose wire or something. I then decided to buy a filter from the local Dodge dealer. Now my fuel pressure is back to holding steady at 8 psi. I guess that not all fuel filters are created equal.