Just installed 10.5 Hotside, EPM O2 dump, and Forge wastegate. Now the dang wideband is at 15.5 -16.8 at an idle. It idles smooth though, no crazy loping or anything. I am currently re-verfiying my injector scaling and smoothing my MAF. Under cruise, it bounces between 14.5 - 15.5, thats normal..Why is the idle a screwy..?

 

Good chance there's an exhaust leak before the WB sensor at one of your newly installed mods. We had a customer with a crack in his O2 housing and resulted in lean readings from the AEM WB, but the car ran fine.