2008 wrx Sti fluctuating idle

Hi peeps. 

I recently noticed since I’ve got my 2008 Subaru WRC Sti back that the idle fluctuates slightly when hot. If I give it a little Rev the idle will drop under 900rpm and go to die then it picks back up again. After that it seems to every now and then fluctuate. I’m guessing boost leak/ coolant temp sense? I left the car running and unplugged the MAF to see if it was that and as predicted it cut the engine so that seems to all be fine. My car also thinks the outside temp is 50 degrees Celsius? - conjiman