closed loop operation

[blue62]

Originally Posted by ike84

When the vehicle is operating in closed loop operations,

Does the MAF provide the main input which is then fine tuned by the NBO2 sensors?

OR

Does the NBO2 sensor provide the main input when is then fine tuned by the MAF?

Logic would dictate that it is the former but I needed to ask if anyone knows for sure.

Short answer:
MAF Which includes Intake Air Temp, TPS, coolant temp, provide the main input.

O2 sensors provide feedback =(Closed loop) info. in the form of voltage to the DME/ECU as confirmation as to what the DME/ECU has already done.
They act as a witness to an event. Yes your going lean or yes your going rich.

The actions of the DME/ECU drives the O2 signal. That is why you see the voltage signal of an O2 sensor as a sine wave. The DME/ECU drives the O2 signal high (rich) then low (lean). Then high, then low, then high, then low. constantly.