Hey I was checking out all your pics and love your Legacy. I was wondering if you could help me out with a question I have. I bought a cat back exhaust and would like to buy a down pipe (catted) but have heard that there is going to be a problem with the O2 sensor not reading properly. Is this true? Can I install the lower section like the perrin and get away with it and still get some power gains or is this impossible to avoid?