I am having trouble diagnosing this this oxygen sensor code that keeps appearing on highway drives. I work for a honda shop and have access to the OEM serive manual. I followed the trouble tree as the book tells you and everything passes the test. I have replaced the sensor with and O.E. one, replaced the ecu and still get the code. The trouble code is #1. The o2 sensor is a one wire sensor. When i read the voltage with my volt meter pierced into the wire it doesnt seem to flucuate up and down like i was taught they should. It will flucuate if i blipp the throttle. The voltage it likes to sit at is .7-.850. If im correct this indicates the car is running to rich and the o2 is steadly trying to lean it out right?? Where do i go from here??? thanks...