has anyone heard of the actual Greddy Emanage unit not working properly?

I am pretty sure the guy who tuned my car either didn't tune it properly or a wire was messed up which caused the car to "miss" right at 6k and a 7500 rpm...

long story short... they removed it and the car now runs fine.... i want to sell the Greddy Emanage Ultimate thing but I don't want to sell it to someone if there is something wrong with it.

here is a picture of my dyno plot.... i am guessing my Greddy system works fine but how can I know for sure?