Air/Fuel ratio accuracy on kmanager and wideband sensor

[soopaman]

need help does anyone know what gives a more accurate reading for a/f ratio between kmanager and the wideband sensor?
the ratio on the wideband shows leaner then on kmanager on the laptop...for example if it shows around 14.6 on kmanager, on the wideband it'll show around 16 and higher.
so basically i need to know which is more accurate or do i have a technical issue somewhere and they should be both reading the same?

[mocchi]

x2 want to know. kmanager vs dynodynamics wideband

[Chernoby1]

There's a difference between the two?!

Just to make sure, we are talking about the same thing:
You have a Wideband sensor and a controller with some sort of display. The output of the controller is sent to Kmanager,
If it IS the case and the numbers are different, Kmanager is not configured correctly.

I think Mocchi is referring to a wideband connected to a dyno(?), in which case it depends where its plugged in. Tail pipe sniffing ain't the best for accuracy. I would imagine that the circuitry of the integrated dyno setup would be decent and of higher quality than your standard in-car setup (mainly coz it doesnt need to be anywhere near as robust)

In general though, The accuracy of the setup is down to the Wideband Sensor itself (usually a bosch LSU4.2 or LSU4.9) and where its placed. The LSU4.9 is like +-0.01Lamda if installed correctly so your'e looking at 98% accuracy. One thing that will throw the sensor off and report strange values is back pressure. Theres a whole bunch of other things that would affect sensor life more than accuracy but would still mess with the accuracy a bit.

[soopaman]

not sure what you mean by the controller... but just got a laptop plugged to the ecu with kmanager open.
i loaded in a base map to run and the readings are different on the wideband to the reading on kmanager.
but now i loaded in a mates tuned map with similar mods and the readings are very close now so not really sure what was happening, cheers for the advice

[Chernoby1]

this is what a wideband looks like:
http://www.ecm-co.com/img/parts/05-03.jpg

If you've got a gauge telling you your AFR's, the gauge is probably the 'controller' for the wideband sensor... ie it puts the sensors output in a meaningful and useable format.

I dont have experience with the Kmanager software, but most others have a drop down box where you have to select which sensor you have and or the controller it communicates with. Your mates tuned base profile probably has the right settings for your particular wideband controller/display/unit. the fuel/ignition maps would have nothing to do with it, just the settings :)