Shuttering problem

Problem here, when I shut the engine off, there is a shuttering sound and feeling from the engine bay. Bought the truck around [101,000], problem started occurring around [107,000 miles]. FYI, I installed the cold air intake around [109,200], so I don’t think it could be from that. When the ac is completely off, it still does it, but very little. When ac is on full blast, it shutters pretty hard. Current miles are [109,848]. The shuttering seems to come from the air pump. Yes, it is a 4 cylinder. I have a video showing engine bay during engine shutoff, but I cannot insert here. Need input before I go to Toyota or elsewhere to fix this problem.