Hey guys, I believe that tech was speaking of the 2nd set part of the downstreem pipes with the Cats on them. NOT the set closest to the headers. EPIQ makes a set of these with bung holes for the sensors to still work and not throw off the computers settings. They say it will still pass emitions. Plus it's an easy bolt-on job, so you can always reverse it if needed. Yes, it is illegal on all states that I know of. But if you pass emitions, how could they tell unless they were underneath your car. Check out these pipes at EPIQ and read the discription.
http://www.epiqautosport.com/pro_boxster_secondary_catalytic_bypass_pipes.php