is my bank 2 sensor 1 o2 sensor bad if it is stuck at one volt and the other side appears to oscillate somewhat normally between 0.1-0.9? i am getting horrible gas milage which did seem to worsen over a few years. i have locked out the phasers and used WSM with sct x4 tuner along with replacing timing components.i dont seem to have any phaser noise or timing components issues. When i first got the truck the dash avg 14l/100km now it sits at 23l/100km. Will replacing the one upstream sensor fix my gas mileage?

 

If I disconnect the faulty o2 sensor while parts are on order will i get better gas mileage in open loop than with a pegged sensor?