FYI i have a JB4 and it compounded the issues with the MAF plugged in. Unplugging the MAF was the only way the car acted somewhat normal with the Injen. I think it's funny that they sell a product that doesn't work properly on a stock car (never mind the fitment with one of the stock electrical covers is poor).
Maybe you guys you update your sites for the Injen to include this in the description (1. Mass-air-flow CEL included, 2. MAF must be unplugged for consistent low/mid rpm power, and a JB4 is required).
But FYI a JB4 is not required to unplug your MAF. The car knows what to do when it's unplugged, it just uses the wide-band O2 sensors, the JB4 has nothing to do with that.