When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Ill put $100 it won't make him happy. Sounds like he wants a silent catless 4" system. No such thing.
Not possible without cats, a proper helmholtz or quarter wave resonator and a chambered/packed muffler. May as well go with how centexguy did his, but it is 3" that way and not stainless.