im lookin in my s300 and notice "use wideband input for closed loop operation" then you adjust target voltage which from what i understand would make the computer make changed to the table and try to get it 14.7:1 or what ever u set it too.. right? so im asking if you can do this so it will kind of tune its self? beats the f outa me .....other wise tune in open loop...right? thanks

 

You do not want to rely on closed loop to tune your vehicle.
Tune the vehicle in open loop then use closed loop if you wish...

 

so in other words YOU make te major changes tahn put it on closed loop and itll do little changes?

 

yes, but after a preset engine load the ECU runs open loop anyway, closed loop is for part throttle. A good way to tell if you need part throttle tuning is by looking at the short term fuel trims (when in closed loop)

 

sooo itll read off an o2 while cruisin basically, but first it reads what u have set on the map and will do little changes according to adjusted map

 

Bnmm It seems like you might need to get a hold of a tuning book which will answer a lot of these minor questions you have.

You will want to tune your base fuel trims in open loop "Not using the o2 sensor for feedback" once you get your car idling at 14.7:1 when you turn closed loop on, you will see the AF fluctuate up and down.

As for the part throttle/open loop comment to add to it, basically the Neptune ecu I have will go from closed loop to open loop at around 650mbar which roughly translates to very slight throttle movement.

I would highly recommend taking your car to get professional tuned after you have read a tuning book or two to gain some knowledge on the subject of tuning. It has helped me numerous times to grasp this subject.


Best of luck!!

 

The "use wideband input for closed loop operation" is more for people who choose to repace their stock narrowband O2 and use the wideband for everything (datalogging, lambda tracing, closed-loop are what O2 can do with Hondata).

Now since the stock O2 outputs a very specific voltage at only 14.7:1 (.51 I think) and most widebands have a 0-5v linear analog output you have to adjust that closed loop target voltage to whatever voltage the wideband outputs at 14.7.

"Tune itself" is what is called Auto Tune. It's another feature you can enable when you have a wideband input, but like the others advised, I wouldn't rely on it.