My AEM uego wideband has been pegging from lean to rich continually, while driving normal and WOT. I am thinking the sensor is bad. Any ideas?

Hello guys, I installed a PDX wideband sensor in my 07 STI, but there were a couple of conflicting parameters to define its location: First, it says that you have to locate it at least 18" after the turbo because if not the heat will eventaully burn it (better yet, 36" if you are going to...