Hello, I know there's probably a thread about this somewhere but I couldn't find one, I am looking for a performance exhaust system that actually gives performance, I have a 99 Gs400 with K&N FIPK intake. Thanks guys also my gs is stock with just the K&N

 

Im sure, there are so many threads on this matter but ill put in my 2 cents. Headers will yield a good amount of power if smog is not a concern. If noise is a problem, it can be mated to the stock mufflers and still make good power. For the mid section, it seems like the popular route would be an X Pipe but from reading around Its not as good as the stock Y pipe. If theres a reputable exhaust shop around and they know what theyre doing they can custom fab one perfect for the 1UZ. As far as the mufflers and performance, changing them out without touching the rest of the exhaust system doesnt actually make any power but aid any changes done, for example, intake, headers, crossover and so on.

 

The one that came with your from factory

 

Agreed. If your keeping the car stockish then keep the stock exhaust and maybe put rear section Borlas.

If it was turbo'd or SC'd I would re-vamp the entire exhaust system.