Hey this is my first post. Idk if I am in the right spot for this but I bought a spec d cat back exhaust for my 06 coupe and while it’s louder, it’s not loud enough. I was wondering if there are any other parts that I can replace on it to make it louder. Thanks.

High flow cats or test pipes.

If you want that awful ricer sound then test pipes all the way. If you want it still "somewhat" clean (cheap exhaust, not a lot you can do besides adding resonators) then go with the HFC.

thanks so much

Louder than a cheap HKS replica? Just straight pipe it, leave the original cats in.... It'll sound super ricey but be loud and barely weigh (or cost) anything

To make it sound less ricey you can replace the center resonators with a magnaflow 11386 or equivalent but that will make it slightly quieter.... THEN you could add resonated test pipes and/or HFCs and sound good as well as be loud.

Im running z1 test pipes, z1 y pipe, z1 single exit and it's not rice sounding its FOSHO loud and deep, the neighborhood loves me 🤗