I replaced the t-stat. No change worth writing about! What kills me is, is that the truck runs excellent. Its just running dangerously rich! I have replaced everything! I mean everything! The one thing that weighs on my mind is the gas tank itself. There is a hose that connects to the tank that is at the opposite end of the filler end. You can't see this unless the tank is out. the hose is that short. The tank hangs until you disconnect it. Well I broke that nozzle when I replaced the pump. I mentioned this in prior posts. And was apparently no big deal, that it is just an air-vent hose. I didn't snap the nozzle off. But it is noticeabbly broke! I know on some vehicles the tank is kind of pressurized. You can hear this when you remove the tank cap. And on some vehicles, if the cap isn't on right, left off, or just loose, it will set off an SES code. But I get nothing. Even a dealer mechanic told me that this was no big deal! Maybe he just has never come across this problem. And I am beginning to wonder now! Even before, the tank never held pressure. But maybe the hose has something to do with something fuel wise. Any inputs on this?