Exhaust
 

thinking of swapping out me exhaust and adding a high flow cat but worried about passing emmissions

I also live in Maryland and just passed emissions. I'm running Berk HFCs and a non-resionated FI CBE. I had no issues at all.

In MD as long as you install high flow cats or the stock Genuine Nissan OEM cats you will pass.

As long as the check engine light isn't on you should be fine. I know people with long tube headers who have gotten through with no issues. Thankfully they don't do a visual inspection. They just hook up to the OBDII port and check for codes.