Why is my 2004 trailblazer loosing oil presure have changed the oil senor and oil
Weak oil pump or oil pressure regulator in the pump. Or worse, it could be a sign that a bearing or other component is failing in your engine. As the part wears it allows more oil flow that the new part. Eventually the pump's max flow rate is reached and the oil pressure starts to drop. What pressure are you running right now. Has it been losing pressure slowly?