hi guys, I’ve noticed recently a slight issue with my STR, when starting from cold. The slightest blip of the throttle and you can feel the revs dip, also runs a little lumpy for the first 30 seconds, when it’s warm it’s fine. Had a good look over it today, there’s a hissing noise coming from around the front of the plenum area, it’s searched high and low to find where it’s coming from, I can feel it but can’t pin point it. Also when turning the car off, you can hear the air gulp (only way I can describe) sounds like a car with an induction kit turning off. I’ve attached a video, just want to know if this is normal

thanks