Since my oil pressure had dropped to scary levels, I decided to change out the pump. I did it Saturday, and what an easy job. If you have any worries about pressure, and a new sending unit doesn't fix it, don't be afraid to change the pump. All you do is drop the lower pan, take off the two bolts that connect the oil level sending unit, remove the 3 bolts that hold the pump,and take off the gear on the front. You can't change the chain without taking off the front of engine, but its a short chain,and it should be okay. I was worried that I might have bad main and/or rod bearings, but now my pressure is like new.