YES! you will need a retune, especially if you delete the rear o2's..

i would go either a single 3", which would be easier/cheaper... or a true dual 2.5".

only reason i went dual 2.5" is because my friend gave me the whole set-up.

 

you sure have a good friend for that gift

 

I really like the y pipe tootall had made,works great
Yes when you get the headers on we need to retune it

 

i guess ill see you next week wheatley

 

i would go with 3"and put 2 cut outs if you go with 2 into 1

 

im gng with 2.5 ory

 

i gained 40 lbs of tq with an x pipe and true 3 inch duals and metel core high flow cats

 

i ran duel 2.25 off my headers then went to the 3"ory. low and mid range seem to get a lot better with the ory. didn't notice any differnce at the higher rpm. i say go with the ory.

 

isn't there a table floating around somewhere that tells you what you should go with based on engine size/power levels?

 

i say if youre gonna do a ORY do a 3". i have Pacesetter LT's w/ their ORY to a Flowmaster Super 40 Delta Flow and it sounds good to me and has decent power too

granted there are guys on here that dont like the sound of the flowmaster with LT's and ORY i like it. kinda has that muscle car sound IMO