after driving a few miles ,and while stopping at a light or coming to a stop(or even when in drive or reverse). My oil pressure drops.But once i step on gas pedal the oil pressure returns to normal.
losing oil pressure when stopped at light or when in gear on 1998 Ford F-150
When mine did this, I found all the tabs on the inside of the oil pan seal broke off and plugged the oil pump screen. Easy low cost repair. Remove the motor mount bolts and jack up the motor(not the truck) remove pan and replace pan seal.