Is Nitrous Legal

New Orleans Inspection:

1) turn your lights on
2) high beams
3) wipers... oh, they don't work? ok...
4) brakes
5) turn signals

and as of only THIS YEAR

6) roll your window up half way and let me check the tint... 35... HAY RAYNESHA IS 35 OK? YEAA BOY DAS GOOD NUFF

removes 3 month expired tag, slaps the new tag on

no popping the hood, looking under the car, sniffer, etc.

So yeah, if you have a problem in your state, just move here

My understading in Texas is that it is legal to have the system installed in your car, but naturally illegal to have the bottle open or activate the system.

It's likely a moot point though, if the LEO feels that he has probable cause to search your car, odds are you have bigger problems than a simple nitrous kit.