When I start and then move the car for first time in the morning, The engine sputters between the 2000 and 3000 rpms. It occours about 0.40 kilometers (0.25 miles) and than it recovers automatically. This only happens on the first start of the day.

Superchips and Supersprint rear exhaust installed (Cat and center not changed).

How could I solve the problem? Does anyone have this problem?
Thank you.