My B2S1 always reads high (about 1.2v), causing the bank to run lean (fuel trims both 0). I've tried 3 fuel ratio sensors, changed injectors, changed ECM,replaced fuel pump, MAP sensor, air cleaner, all with no change.

I installed new spark plugs and shuffles coils with no change. I can disconnect 1 or 2 of the front coils with no change in rough idle.

The heater control and sensor output "toggle" when engine cold, and when engine warms up the heater control stays near 12v and the sensor output stops toggling and stays about 1.2v (Vref-Vsensor).

I have 60 psi of fuel pressure at rails. Rear bank runs fine with any of the3 fuel ratio sensors installed.

I've been dealing with this since I bought the car 6 months ago, and am really frustrated. PLEASE HELP.