Hello all. My Aerio randomly stopped idling properly when I started it in the morning, and after being taken to the shop I was told it was the IAC valve causing the problem. They said it just fell out. I went to buy one and install to find I do have my IAC valve, but the whole in my throttle body is for something else. Seems to be a plate of some sort? When the hole is covered the car idles perfectly then immediately can't hold idle when uncovered. Can't seem to find what this plate would be called. Any help would be greatly appreciated.

The plate that I am missing. (Image found from eBay listing)

My throttle body with the mystery hole. (Confirmed is not IAC valve or TPS)



Edit: found a junkyard Mitsubishi mirage that shares the same part, still not sure what it is exactly, but it's installed in my Suzuki now and running perfectly.