got this problem my 2 valve 4.6l oil pressure went from pressure on the gauge to 0 now it does it when u start the eng up good gauge pressure then goes to 0 if u let it sit 2 to 3 mins it start the eng again it has good pressure on the gauge then after a minute it will go to 0 i replaced the oil pressure sensor and oil filter still the same affect doesnt seem to have oil going to the head looking thru the oil cap friend said it could be a clogged screen in the oil pan on the pick up could it be that???? and im not getting any eng codes