If you are spinning any of your wheels while accelerating then the engine seeming to go into "limp mode" is a reaction by the Power Control Module (PCM) from the Controller Anti Lock Brake (CAB). It is doing what it is intended to do when the Acceleration Slip Regulation (ASR) system is active. The CAB is receiving inputs from the Transmission, The wheel speed sensors, the Parking Brake Switch The Stop Lamp Switch and the ESP Off Switch. Check all the wheel speed sensors, your parking handle/switch and try turning your ESP switch off. Assuming your basically going in a straight line, if not then the Electronic Stability Program (ESP) also will play its part.