I just got the light of death on my fj. I saw the engine light come on along with the ESP light (the car with a squiggly line). I get back to the house and hook it up to the code reader and get P0031 HO2S heater control circuit low (bank 1, sensor 1). I did some online research and I believe it's the right upstream O2 sensor. I just wanted to see if anyone else had this issue with their FJ. I was stationed in Germany where I bought the FJ. It only had 7k miles on it when I purchased it. I've had it under 2 years, bought it in 2013 and came back stateside in October. The vehicle was put in a shipping container and then on a boat for 2 months before getting to LA. The reason for the long story that seems irrelevant to my issue is the fact that being its a 2010 being bought in 2013 with so little miles had extensive rusting. I've busted numerous nuts and bolts doing minor maintenance. I'm wondering if this might have anything to do with the front sensors taking a **** on me. I also am hoping that this isn't something that is potentially going to turn into a bigger problem. She will sit until I get it figured out so I don't cause further damage. What's the standard procedure for changing the sensor? Do you typically change all of them or just the one that's bad? Any help is much appreciated.