I have an AEM guage in my car and my 2006 Nissan Frontier actually uses the same O2 sensors on the drivers side from factory....
If your stuck just hit up a Nissan dealership, they may have them in stock.
Good to know. I'll drop into a dealer and get a price. Autovalue thinks they can get one in but they want $140. If they are going to be that expensive then I'll pull the sensor and plug the hole after I have it tuned.
Another reason to run a head shim, I guess.