This might be a long shot, but does anyone have the V3 stage 2 map saved somewhere?
I updated to the V4 and since have had issues with the car throwing the "Low catalyst efficiency" code. I contact Cobb and they informed me that they are no longer supporting the stage 2 and 3 OTS tunes and to find someone local to tune the car.
Has anyone else had this issue? I am running the Nameless divorced downpipe, but never had it throw a code with the V3.
I have not swapped the downstream O2 sensor yet, as I found the timing of it all to be too convenient.