Injen intakes not as loud as they were?

[JSting]

Hello guys my first post ever about my car. A couple of months after getting it I installed injen intakes and they sounded great, nice induction noise when accelerating and load air whip sound once letting go just like in some youtube videos. Then I ended up buying some HKS blow off valves which also sounded great once I put them on loud whistles they were amazing. Then one day I went out and as I went into the highway I noticed it was a tiny bit sluggish when I accelerated and let go the intakes and bovs sound was supper low and was more of a low whoosh. I thought maybe the bovs broke somehow i checked all the hoses and looked good. I decided to take everything out and noticed the driver side turbo was wet inside while the passenger side was clean. I decided to just leave the intakes thinking it might have been the bovs and noticed the intakes dont sound the same either like they did at first. Took it to the dealer thinking it was a turbo issue but they said no that everything is fine. And that the turbo leak which was oil is something normal. They also checked for coolant leaks and said there was none. What can it be then? I cleaned the intake filters but did notice some dust inside the intake tubes that I didnt clean can it be that?