Nobody makes a CL-S bolt on hi-flow cat. Random Technology makes one that will work, but it's for a CL and it has a 2" pipe vs the CL-S 2.5" and the O2 sensor wires need to be extended and the holes might have to be drilled out bigger. http://www.ultrarev.com/product.php?productid=40797The best thing to do is to get a universal 2.5" and have it welded up. http://cgi.ebay.com/ebaymotors/2-5-C...QQcmdZViewItem It's a lot cheaper but may be illegal for a shop to do this. Check your local laws and shops before you decide.