Can you put heet and injector cleaner at the same time?

When I first bought my Sunfire, I used both of those products to try to solve a problem with my fuel gauge being way off.

I'm sure I tried them both in a short period of time, but I can't swear that I used both in the tank at the same time. I sure hope I didn't, because it sounds like it could be a really bad idea. You never know what might happen when you mix chemicals.

I'd try them each in it's own full tank of fuel.