I was detaching a battery cable and accidentally connected the two battery terminals through the socket wrench (Damn 6'' extension), it was also still connected to both the car cables when the sparks started flying. Since then my idle bounces from 500-1000rpm once the car starts getting closer to operating temperature. Is it possible I just fudged up the IACV or could I have ruined something more expensive like the ECU or Main Relay?

Edit: The engine is actually rev matching with the tach as it bounces so I know the RPM gauge isn't jacked up.

 

Probably not an answer you want to hear but....

I did the same thing years ago, the problem went away on its own. I wish I could tell you specifically how to fix it but I never found out what actually happened or what was tweaked/damaged.

 

Yeah true not exactly what I wanted to hear but you were right on about the problem going away on it's own. At first the idle would bounce at every single stop, then it started only doing it every other stop, and now it only does it for about 2-3 seconds after I stop then it idles normally although it's a little rougher now. Idk what to look for cause I don't want to start replacing good parts, and cars don't just fix themselves so I can't let this one go lol...