how to smooth o2 sensor feedback

[ryan_axberg]

Hi, I am working on a project that closed loop is working and it is pretty good at idle, but when I am at part throttle in gear when it has some load on it you can see that it goes too rich then too lean. I know you want it to go slightly under stoich then slightly over stoich but it is going way too much. Anyone know how to make the feedback from the o2 sensors not make so big of changes? thanks

[blindsquirrel]

Easy. Buy a VW/Honda/Toyota or whatever that use a wideband and the associated strategies for primary fuel control. Narrowbands that work like you want do not exist because that is not how they work.

[kingtal0n]

hes so cheerful and happy all the time!!!



hehe, what he means is, you should do an internet search for 'how narrowbands work'
And learn that,

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They switch from 0v to 1v very quickly. They cannot be held very easily at anything in between 0 or 1v.

I'll give you some ideas though
In many computers are options for switching target voltage ranges. Most default like .550v or .450v or something like that.
But, if you set the switching point much higher or lower, say .2v or .8v, you can dial the average air fuel ratio up or down some (for economy purposes usually).

Another thing you can do is use an simulated narrowband output, since its just a 0.022v to 1.022v range its very easy to setup.
Some widebands have analog outputs, for example:
15.5:1 air fuel ratio analog voltage: 0.122v
15.1:1 air fuel ratio analog voltage: 0.988v

If you configure the analog voltage like that, the OEM Ecu will hold the a/f ratio between 15.1 and 15.5 all the time (For economy purposes).
-> You could alternatively use an arduino microcontroller to do this based on real-time narrowband feedback (no need a wideband)

Keep in mind narrowbands are only useful because they are cheap for mass produced cars that don't need performance or economical tuning.
Narrowbands generally serve no purpose for performance or self-tuned vehicles (if you are learning to tune, you will use and rely on widebands)

If you are having trouble with the analog voltage and terminology you should read up about basics for electronics, RCA Circuits stuff
https://startingelectronics.org/
https://www.electronics-tutorials.ws/
https://learnabout-electronics.org/

Good luck lots to do

[ryan_axberg]

I got it working like I want, just had to mess around with different settings a bit.