Subject: Can O2-sensor make engine run too lean?

From my own experience unplugging the O2 sensor hides many of our fuel injection problems. Not just the O2 sensor. For a long time my bus had a horrible hesitation from a stop. I unplugged my O2 sensor between repairs so I could tolerate driving the bus. I ended up replacing the AFM, finding a few vacuum leaks, and adjusting the throttle position switch with the help of my friendly neighborhood mechanic. I look at as the O2 sensor is the final gate that all other sensor information passes through. Definitely look at all the other parts of your FI system.