Just purchased a ’fifteen Civic SI coupe, I just planned to do a downpipe as well as a tune, are there manufacturers it is possible to advise? Wouldn't it be improved if I bought a complete exhaust program? (does that include a downpipe?) Im a noob, thanks Technically, the “downpipe” https://bmw54209.mysticwiki.com/941184/m3_g80_downpipe_for_dummies