[rodbls]

OK, a Precat is simply a catalytic converter right on your downpipe off your exhaust manifold. Then front and year manifolds "Y" togeather and there is another Cat. If you have a set of cats before your main cat then you have a Cali spec. If you dont know what a cat looks like, it will have a heat shield on it, and be much wider than your regular exhaust tube. It will also have O2 sensors in it (there will be 2 wires connected to the O2 sensor that kinda looks like a spark splug in your exhaust). The precats will be smaller than the main cat, but will look similar in shape. Hopefully this gave you a little better idea of what to look for. If you have a Fed spec then the exhaust manifolds will both just go directly to the Y and then to flex pipe, then the main cat. If you look at upgradeing exhausts, they are called "Cat Backs" which means that everything from the main Catalytic converter back is new.