seems like the car is huntin for a gear

[Dragon]

First, my car is an automatic. I notice if I'm driving and take my foor on the gas, the car feels like it is hunting gears, tach varies from 2-3000 rpms as it slows down. It all started rigfht after I installed a new stereo in my car. Also, it seems to go away once the car has warmed up.

I didn't hook the stereo up to the nissan wring harness. The previous owner of the car splaced in wires to attach to his deck, and just used those spliced wires when wiring in my decks harness.

Anybody have or hear of this problem?