The oil pressure sending unit is underneath the oil filter housing assembly. It is very easy to access with the mid pan off (which you have to remove anyway for each oil change). It is a very, very high probability that it is just a gauge issue (well documented on this forum) but to be safe, you can temporarily remove the sending unit and install a generic sending unit or line to a temporary gauge. While you're under there, you might think about removing the oil belt cover and inspecting the belt and pulley. If all of that is good, you can be 99.9% positive that your car is making good oil pressure.