Anyone know of any devices to shut off fuel flow when the nitrous runs out in wet systems?

 

the NX gen2 kit comes with a fuel shut off if fuel pressure is too low

you'll know if you ran out of nitrous and running rich for a sec or so won't hurt you, the danger is the other way around and that's what the fuel saftey shut off is for

The Maximizer has a A/F reader that will shut off the nitrous/fuel in case of bad a/f readings as well