I have an Injen Cyborg intake on my P5, and when I shut the engine off it makes a strange sound. At least I think it's the intake. It sounds like a vacuum cleaner powering down. I can't think of a better way to really explain it. It's like a suction sound, and then when the engine powers off the suction sound continues to decrease in volume until it eventually quits about 2 seconds after shut off. Is this normal with a CAI or is something fried?