Hello everyone I have an 03 G35. I replaced the throttle body and afterward I did every relearned procedure I could find but I am still running at just over 900 rpm's. I also found and corrected a couple of vacuum leaks without results. I checked inside the TB and I can see the butterfly is slightly open. when the engine is turned off.
So at this point I am assuming this is the culprit. Since the TB is open the IAC valve is basically ineffective in regulating the idle speed. I'm considering adjusting the TB butterfly by moving the screw at the top of the TB Unit.
I would appreciate your input as to whether this is a safe thing to do or is there another solution.

 

inside of the TB in case you were wondering

 

I would return it and get a new one.

 

Thanks it is not clear to me what the external adjust is for. but i decided i'm going to return the unit and attempt to adjustment in the replacement if it still has the open butterfly.

 

So the reason for this exercise was to reduce the idle back to normal around 650 rpm. The original TB Unit was damaged but further diagnosis narrowed the problem to a vacuum leak. I changed the Valve covers and discover 4 of the spark plug tube seals were cracked, replaced them. I then took every hose I could and replaced or repaired. After assembly I followed the close valve, pedal released, and ECU reset procedures. Turned it on and after a brief warm up period run at 650 rpm and no P0507, Success I appreciate everyone's help.