If you're running a catless downpipe, you will get a CEL unless you've got a tune that disregards the insufficient O2 sensor CEL, or whatever it's called. No tune required for some of the CAIs, the SPT one for example. If that BOV isn't recirc'd, the car will likely run like crap without a tune. If you're running stock turbo, stock injectors, and stock BCS, you can probably run the Cobb Stage 2 map and be fine, but you'd likely happier with a custom tune for your set up. I haven't looked at the Cobb AP maps available for your car recently, but they may have some off the shelf maps that might work with a CAI.