Forgive me if this has already been discussed ad infinitum, but search seems to be horribly broken at the moment.

So my old 60-1 died and I'm now running a 62-1, which we just got everything put back together tonight. However, when I am WOT, as I get near max boost (15psi) the check engine light comes on, and stays on until I let off the throttle.

Would this be due to knock? The car was tuned for 15psi but this turbo is a little bit bigger and flows more. AF is around 12:1 at the time it comes on, according to the wideband gauge. I'm planning on calling the tuner tomorrow but was wondering if anybody has any ideas. I have a feeling it's knock but I didn't think that light would come on for anything anymore with running an EMS.

 

The CEL can be configured to light on many parameters when using the AEM EMS.

My guess is your tuner has set it to a certain parameter and you're exceeding the set value. What it is though is entirely arbitrary.