does the ems utilize the stock upstream and downstream 02 sensors?

 

yes.. i am using stock ones

 

just the primary is needed, the one in the o2 housing.
i removed the 2nd one. That one is only for emmission.
Be sure not to lose it. If you need inspection w/o the 2nd one you'll get a CEL.

 

^^^^ can I put the UEGO wideband in its place?

 

It doesn't use EITHER ONE. You can configure it to be read but it will be inaccurate. Narrow band sensors do not have a linear output. Put the WB in and call it a day.

 

wow it seems like I keep getting conflicting answers..... I might just have tyo call AEM direct or my local tuner

 

^^^This is how I have mine

 

Can I just remove the oEM rear 02 sensor and put the UEGO wideband in its place? would it still read properly?

 

It is pretty far downstream.
There should be absolutely NO confusion. The stock OEM Narrowband sensor is NOT calibrated to be read by the AEM or ANY EMS for that matter. If you can put it in the O2 housing. You are more than welcome to pm me if you have any questions.

 

And you are correct in your setup!

 

/\ I have two friends doing it this way and this is how im going to run mine.

 

That is the correct setup

 

so when its in open loop the AEM doesn't use it?

 

I could never think of a way to get the AEM to cycle around 14.7 like the stock ECU does. I don't think it has the required logic. I wonder though what would happen if you entered the calibration curve of the narrow band sensor, and setup O2 feedback with a pretty tight control limit (once the map is close to 14.7, which would require a wideband). It might simulate the stock ECU's behavior to some degree. Either way, it's not worth it, since you need a wideband to do any meaningful (and safe) WOT tuning.

 

The AEM NEVER uses the STOCK sensors or even any aftermarket sensors. IT NEEDS to be be calibrated to use or read anything inputted to it. Doesn't matter open or closed loop.
The EMS will be in OPEN loop ALL the time, unless a wideband is specifically designated to read and give feedback to the ems. Then you can program closed loop status.