[frankwjr]

? H/F cats on stock headers? And you want to install long tube, correct? then the current H/F's will not work, gonna have to change to the long tube ver of the H/F or go off road if no emissions..

is the car tuned? if not then the car is not realizing it's full potential regarding any mods..they go hand in hand..

give a shout out to dynoSteve at RDP...awesome tuner and he has special forum member pricing on his website...worth the time IMHO...good luck!