2005 sts v8 reduced engine power
 

Hello I'm new to this forum but in need of some serious help and hoping someone can. I have a 05 sts v8 and after driving car for awhile sometimes it will shut off off while driving and say engine power reduced after letting the car sit for awhile I can start it and drives fine untill whenever it happens again. It's happened 3 times since buying the car and not sure what the problem could be. I've changed the throttle body senors thinkin that could possibly b it but I'm no mechanic. Car check engine light also comes on and off when it feels like. Someone please help

thanks
Garrett