Protege1.8L

Ok, my check engine light is on, and I had it checked out. Mazda said that it was my Catalytic Converter. I just had this replaced about 1-1/2 or 2 years ago. Mazda charges a lot for these. I've been told that they arent the same as the converters on other cars because its not below on the pipe its specialized like its on the downpipe towards the engine, is this true? Where can I get a new Catalytic Converter without spending an arm and a leg, because I can't get one of those universal ones if they are that specialized, right?
THANKS SO MUCH
-James