Turns out that leaking valve is seized in the threads.
I broke off part of it trying to unscrew, and now it is indeed a $140 sensor replacement job. Makes me so mad they found a way to turn a $10 tire replacement into several hundred dollar robbery. Fuck Nissan! Fuck all of their engineers, executives and shareholders! Go to fucking hell you criminals!
You made valve stem out of aluminum, which of course seized from humidity. Valve stems used to be made of brass for a reason, assholes! Reason being brass did not seize. Rot in hell all of you at Nissan! I want you robbed just like you are robbing your customers, scumbags!