My 2002 gran prix supercharge has a oil leak behind the power steering pump

It could be your valve cover gaskets, intake manifold gaskets, or possibly the timing cover seal. If you have between 90 and 120 thousand miles on it I'd suspect the intake manifold gaskets. Look for coolant pooling on the top of the intake manifold as well. You might even be getting coolant in the engine as evidenced by a white milky goop on the oil dipstick or under the oil filler cap. The GM 3.8L V6 is notorious for intake manifold gasket failure at the above stated mileage. Hope that helps! Jim