engine power reduced code

[babydieselholder]

So I have a 2020 gmc at4 with this little duramax and love it over all. One problem I'm having tho is it'll pop up this engine power reduced code when I'm working the thing like bucking wind or towing. the truck has an s&b intake and was tuned accordingly. it is deleted and tuned. another thing I'll have happen is it'll pop up that code and run the engine fan wide open on random and rare occasions when I start it in the mornings especially if its a bit cooler. Any ideas or fixes would be appreciated or if any one else has had this issue what you did.