"Catback", it means from the catalytic converter to the tailpipe.
You might want to avoid removing the cats. You won't pick up that much, and even if your state has no emissions inspection, you could be pulled over and issued a ticket: I can smell a missing cat a quarter mile away, so can the police. A fast car that's emissions legal is much cooler than one that isn't.
01 M roadster, F: GC/Koni short coilover struts, Eibach, Wilwood front brakes, GC tubular swaybar. R: TC Kline springs, short Bilsteins, IE sub & swingarm bushings & shock mounts, 3.23 gear, Rogue dual-ear cover, Eisenmann 4x83 pipes. MISC: Sport mode, Rogue pulleys, keyless, RG Motorsport intake, OZ Superleggera 18" 3 piece.
06 Hemi Durango
04 G35 Coupe
05 Scion xB
07 Scion tC
89 Reynard F2000