My friend just got an FIPK put in on his car and his check engine light came on. He has the same setup I do and everything seems fine but why is the light on, any suggestions?

 

Ensure the IAT sensor is plugged in or he didn't damage it. Same with the MAF, though if that is not plugged in you would know it as soon as you started the car, MAF sensors could possibly be damaged though .... ??