Can i use a Stage 2 Accessport on my 06 STI safely w/o haveing done anyother mods?
if so should i get w or w/o cat-back?

 

To run stage 2 you at least need a dp.

 

If you are buying an Accessport only, you will be on Stage 1 map. You need at least a downpipe to run stage 2. Buying a cat-back exhaust only will keep you in Stage 1...you need to buy a turbo-back exhaust which includes the cat-back and downpipe.