Tuning after changing out factory exhaust system to aftermarket on sti

Ive been searching for anything in particular in tuning adjustments for my sti. Im changing out my stock exhaust for equal length header uppipe and downpipe. I have a cobb accessport and accesstuner software just no real info or what modifications I should make for aftermarket exhaust! Please someone point me in the right direction! Thanks

i just replied on your other post but it will need both fuel and ignition checking generally it will run leaner and need timing removed

I appreciate your fast response. Is there any links you could share on removing timing. New to this but fast learner thanks