O2 sensor eliminator — why?

[ChipBeck_imp]

I am speculating but I think that with the O2 sensor eliminated the computer is operating in open loop. In open loop the computer uses predetermined fuel maps which are slightly rich. The 2 main systems are speed density or mass air flow. With speed density the main inputs are RPM and Manifold Absolute Pressure. Mass Air flow uses a meter to actually try and measure the mass of air entering the engine. When the O2 sensor reaches 600 degrees the system goes into closed loop and primarily uses the voltage from the O2 sensor to adjust what is called the fuel trim to achieve 14.7 to 1. I am going off memory and I am sure it has advanced since I worked on this stuff. In open loop the fuel tables are slightly rich which is why the auto companies try to get the car into closed loop as soon as possible. This drove the need for O2 sensors with heaters in them. Rich can mask a lot of issues but creates more pollution. It could be that in closed loop one of the sensors like the engine coolant sensor is faulty.
I am still leaning towards the Throttle Position Sensor but it is hard to know. On my Bandit 1200 the TPS effected ignition timing only. I do not know if Honda is also using it to effect injector pulse width.
This is where I think the dealer would be the most help. There may be a technical service bulletin but at the very least they have flow charts which will guide the technician in his diagnostic process.
I just looked at the Power Commander site and it does state the Sensor eliminator prevents the ECU from going into closed loop operation. Hope this helps. I think some of the earlier posts did a great job explaining closed loop operation as well.

Toro,

3 more questions.

1. So the CB11 should get slightly better mileage with the 02 sensor working right?

2. Is it the 02 sensor that leans out fuel to keep the bike at 14.7 to 1 in the thinner air at high altitude?

3. Would a CB11 ever run poorer with the 02 eliminator or would it just run slightly rich sometimes?

Thanks.

Chip