The vehical is a 1999 Ram with a 5.2 Just had an oil change about 500 miles ago, it lost all oil pressure before(right after a head was replaced) but i changed the oil filter and it was fine after that. On the way home from work today pretty much every time i would come to a stop I would lose oil pressure. Is this most likely the pump? or something bigger like the rear main? Has anybody had similar problems? let me know, Thanks!
The vehical is a 1999 Ram with a 5.2

 

Check your oil level. If your level is good, I'd guess pump. If it was due to a seal your pressure wouldn't come back up cause you'd have no oil. Since it seems to be dependent on engine RPM, I'd guess pump.

 

had similar problem. oil gauge went to zero whenver I came to a stop, or on a sharp curve. Check your oil level. I had lost 4 quarts over two months, so it finally triggered the gauge. found out that I was leaking oil into the intake manifold. shoudl have known! oil consumption + no visible leak+ spark/knock = infamous dodge defect of intake manifold plenum. I have 99 dodge ram. had same problem at 40k miles. Now at 84k, I have same problem and Dodge won't pay this time. ITs costing me $800 to fix. there is a tsb on this, so that's how I got them to pay first time (TSB 09-05-00). not sure if this is your problem, but check it out. you can see the tsb at..
http://dodgeram.info/tsb/2000/09-05-00.htm

 

If there is a TSB, they should pay again, just cause they fixed it once and didn't do it right doesn't mean that they don't have to do it again.