The AEM is the absolute worst unit on the market. I have never, ever, one time, EVER, seen one of those things be accurate. I don't mean to frivolously slam your product, but that's what the deal is. My recommendation would be to not take the time to wire it in to the Haltech (which is easy, by the way; just grab the 5V O2 output lead and send it to the Haltech's O2 input lead).
I recommend using a wideband that utilizes an NTK sensor.