If you have badmab header already why buy new header? Cheaper to just get the dp.
Going to get a lot louder once you put the dp on too! FYI
Oh ok, Ill just go with the 2.5" catted DP, I know it will increase exhaust noise by 15-20%, but heard the gain was noticeable. I wonder what all of this with a PCM dyno tune will do, hmm...
My MazdaSpeed and WRX had catless 3", great gains, but annoyingly loud lol.
2009 Cobalt LS XFE U74
Mods: K&N Typhoon Intake, Option Cat-Back Exhaust, Cosmo Short shifter, Maxxim Ahead 17X7's, MPx shorty antenna, FE5 Strut/shocks, Tein S Techs, Moog endlinks, Moog spring seaters, ZZP shorty header, LSJ downpipe, LNF front grille