You really should search the forum.
The system is in 4 parts:
1) Headers, includes primary cats, 4 O2 sensors (fore and aft on each cat) and exhaust gas temp sensor. You don't want to mess with this if you just want to make more racket. It's a pretty deep rabbit hole.
2) "Section 1" a.k.a S-pipes, includes secondary cats. Can be deleted to increase volume and rasp, but will increase HC emissions. I still passed Cali sniffer smog.
3) "X-pipe" a.k.a. cross-pipe, crosses the streams to smooth out pulsations, stock has a "silencer" (pre-muffler) to eliminate rasp. Aftermarket is just 2 pipes that come into one for a couple of inches, then split.
4) Mufflers (cans)
You can have your way with 2-4 without a CEL.
Now see here. Many other brands available.