I can tell a differance when im not running my header I think its a big one myself I do not have a high flow cat either. Header FTW.
NW Posse#10 Team Duratec#69
F2 Header, Steath Exhaust, CAI, AR103, Tuned by Randy Fswerks, DGR Coil Overs
DOMINANT front and rear LCA DOMINANT endlinks Massive toe and camber arms