No but it keeps the o2 sensor out of the exhaust stream completely and doesn't cost any extra.

 

There was almost no difference in exhaust note or volume when I went Berk 63 with the stock cat back. It makes just a tiny bit more noise but almost none. When I did an intake that was noticeable but not the TP.

 

You didn't get that tinny rattling sound with the OEM exhaust? The test pipe improved performance noticeably, but the sound quality really went down hill; when I started my car for the first time I thought something was unbolted, but it really was that the test pipe changed all the Helmholz magic into a tinny rattling mess. I wonder if the people who say they didn't hear much difference is do to user perception, or if there is some difference in the test pipe manufacturers. If seems Berk is the best sounding test pipe from what I've read, although I'd think a pipe is a pipe is a pipe. I'd love to go Gern pipe into OEM, but it's just too much money for me.