[Carlisabadman986]

Originally Posted by BruceH

The cats on the headers have the O2 sensors. You are getting rid of the secondary cats which do not have sensors. Here is a link to Top Speed's cat bypass pipes:

Porsche 986 Boxster 2.7L & 3.2L Including Boxster S 2000-2004 50mm Bolt-on Cats Test Pipes

The website does say "will not pass emissions" but everything I've read here insists as long as you don't mess with the first set of cats you are fine (which makes sense given the location of the O2 sensors). For around $500 the pipes and the muffler seem like a great deal and an excellent way to beef up the otherwise tame sound, also $1000 less than the Fabspeed system.