Never had a smog test done. I don't believe NH does such, but don't quote me on that. It has to pass emissions, electronically and "visually". Aka no CEL if you're swapped I'm guessing you're tuned so as long as it has been disabled your fine or run a couple of spark plug non foulers that have been drilled out to 1/2" ID between the last 02 and the DP. Of course that will make the computer happy, but you need "pass" the visual part as well, this require knowing someone with a inspection license.