Been working with a super helpful Tial rep as I/we thought it was the Tial QRJ bypass valve causing the issue. We've tried several different springs, along with a helper spring. Checked vacuum pressure, vacuum hose, etc.

Today I pulled off the recirculated pipe off the valve that goes back to the intake filters. I wanted to visually see the valve oscillating open/closed while I had a friend apply slight throttle. What I found was that the valve looks to be behaving normally, and the sound actually seems like it's coming from the intake filters. I popped one of the filters off and held my hand half over the opening, and when the fluttering sound starts to happen it almost feels like the a "flutter" of air rushing in through the intake pipe. First thought was throttle bodies, but they seem fine. https://imgur.com/aWP4SZJ

Anyone seen anything like this before? I'm really at a loss, getting frustrated with the whole thing. My tuner is waiting on me to sort this out so I can get a new E tune.