Strange idle problem with GTM SC Stage 1

[wind.zero]

I sent an email to my tuner and Sam at GTM, but I wanted to see what the other FI people thought about this idle problem. I have had this problem since the SC kit was installed several months ago. Other than this idle problem, the kit has been fantastic.

Everything pointed to slight exhaust leaks I had with some test pipes. So I put the stock cats back on using all new OEM hardware including inlet/outlet gaskets. Going back to the stock parts fixed the daily SES lights, so I am 100% sure there is no exhaust leak now.

However, I still have an erratic idle. This is video of the problem. It happens at least once a day. What do you guys think might be causing this? You have to watch the entire video, but the car tries to die at about 40 seconds.

EDIT
The problem usually happens after exiting the highway and stopping at a traffic light for example. I was just able to get the video on a restart of the car. It only happens when the car is well warmed up.