It is only nec if you want to know what gear you are in. LOL!!. IIRC in NJ you would fail state inspection if it did not work, I dont know if NY state will give you grief over it not working.
I would just to be on the safe side. Laws are shitty sometimes so you never know what kind of hell they'll put you through. And if CA for your location means California, then I'd def do it as they are strict as fuck lol.
