The other day while driving I noticed I had lost a lot of oil pressure. I've owned the truck for nearly six years and the oil pressure has always been excellent. I keep a close eye on it and it was like it dropped overnight. I went from around 60psi at highway cruising speed (~1700 RPM) now down to 30 psi. And my hot idle dropped from 25 or so down to less than 15. My buddy's snap on cpu confirmed that the gauge is displaying exactly what the sensor is reading. The first thing we can think to try is the oil pressure switch? Injectors are good and I haven't been making any oil. Any thoughts?