in all tech terms you have a better chance with the turbo running then without, when you mix that air with all the ext is dilutes it in a sense. you might just be better off doing a tune up, having you catty checked, It sounds from what you explained you probly live in California, i know this test oh so well as i have to get ready for it every other year myself, and there not easy to pass with the volvo's. id take it to a mechanic's shop and tell him you want a straight smog test done to see if you will pass or fail, this way you get an idea of what your actually going to have to do.