EcoboostDave

To switch between tunes? I switched to my 91 tow tune but for some reason the check engine light comes on with it. So I wanna go back to my 91 perf tune. I've done this before in the past few weeks. I just wann make sure I'm not going to fry the cpu by switching back and forth thru tunes.

reward69

I was told by both livernois and 5* that it doesn't hurt anything to do this. I to had the same concerns?