Here's the 1st post I made in which it gives detail, but short story long was having psi issues in the morning. The relief valve in pump had a few buggered up places so think it could have deff been sticking as well as o-ring was dried out on pickup tube.
when the psi would bottom before repair it would gradually drop and if you gave it rpm up to about 1K it would pump about 20psi now it shows 50 for about 15-30 secs and then just goes to dead zero and if I clear code it come back on immediately.
Pasted from my intro post:
Upon the test drive I drove it like I stole it and made the oil psi bottom out at idle and valve train NOT happy. Therefore it's currently sitting in my garage with the oil pan off awaiting me to get home tonight with the correct harmonic balancer puller to finish tearing her down. Already have the pan and pickup tube off and the o-ring was definitely dried up and possible culprit but hoping to find a sticky relief valve in the pump tonight also. I drove it for about a week after buying and every other morning or so would bottom out on oil psi after about 2-3 miles from my house at first stop light and then never give another issue. Before anyone suggests sending unit already attacked it from that end first and confirmed it indeed was losing psi not just the gauge saying so. When it wasn't giving issues engine was Extremely quite for a GM 6.0, ran a compression check before tearing into it and had 170 across all cylinders and inside of engine is immaculate for 175K miles. Hopefully with some TLC she'll be a good one to last me a while!