Sup guy, please see below..

2012 Sierra Denali AWD 6.2L
224 comp cam with VVT delete
Tuned on 93 octane

Can I run e85 in my truck without any problems (it has a yellow gas cap). I have never ran e85 before and just curious. I heard you have to change the fuel pump and injector to run e85??? But doesn't seem right to me since mines came factory with yellow e85 gas cap.

Thanks

 

If tuned for 93 then probably not...check with tuner

 

Depends how it was tuned...doubtful it will be perfect right out of the box.