I have a 2007 g35x. My bank 2 sensor 1 has high o2 voltage at around .9v when at idle. Even when the car is not running (just on position), it registers .9v. It does fluctuate up and down while driving and does drop to ~. 4v when letting off the gas.

There are no codes and the fuel trims are about equal on both sides which generally is around 0% for LTFT and - 10% to 10% STFT. The car does not drive rough or misfire. I get about 15mpg with mainly city driving.

Is this normal? I am thinking it's a wiring problem because my front o2s were recently changed along with my injectors. This problem was occurring before the replacements and I've tried switching the o2s from side to side. What should I test next?