Bad site detection/ frustration

I think the one thing I don't like about insulin pumps is the mystery of unexplained highs that wind up being due to " bad sites". I wish there were a technology that alerted us to the fact that insulin isn't getting into the blood stream. Is it a virus? Sneaking snacks? Miscalculated carbs? When it is due to a bad site it is very frustrating. We don't know until we try a new site and the BG goes back to normal. 

I'm with you on that one. Sarah rarely has bad sites/insulin, but when it happens it always throws me way off. Then we do a site change and everything is right with the world again.