Hello and welcome.
The reduced engine power is usually caused by a check engine light. When the Powertrain computer sees a problem in a sensor or the emissions system, it turns on the check engine light and stores a code. This could be for many reasons. The computer systems would need to be scanned for codes.
There are many engine codes that will also send truck into reduced power mode.
When in reduced power mode, or certain check engine light codes, the stability system will also be disabled, and turn that warning on.
Again, a scan of the codes would be needed.
Being an 07, this truck would still be under warranty.
Welcome. I must agree with Joel. The Stabilitrak is disabled due to a fault in the engine. Given how incredibly advanced this system is, we will need the code from the engine computer causing the reduced engine power to start diagnosis. Can you get it scanned? Most part stores scan for free.