O2 Sensor problems of the 2012 Infiniti QX56

Was driving home, a/c was on, all lights was on, all of a suddenly lost of power to the engine and while going up hill, so I floor it so the vehicle so I can get past over the hill then I started to smell something through the vents like it was on fire coming from the engine bay so I pulled over and turned off the engine pop the hood but didn't see no fire, then when I tried to start the vehicle back up it wouldn't so I waited for few minutes and tried again, the vehicle started back up so I went on driving again but it didn't show any thing on the dash no check engine light at all. It done it again lose of power to the engine and I started smelling something burning like metal coming from the vents again lucky I was close to home when it done it again, I shut the vehicle off and put the scanner on it, it throw out 3 codes but it never showed up on the dash saying check engine light at all. For the 3 codes one was for fuel pump other was for 02 sensor and the other was ecm I believe, wish I wrote them all down.