No. It runs fine, have a slight backfire every now and then but even still, its not often. Actually runs a little better (seems to pull harder) because it holds boost better, doesnt leak like the stock unit. The only reason I had to go VTA is because I could not angle the BOV to accept the recirc tube. I think its because of the intake though; the way its angled. People say it will run rich between shifts and ruin your cat. converter, but our cars run pig rich anyways...so...its up to you......i have my own opinion, but its just me, we'll see in a couple thousand miles...
it honestly sounds good! I tried venting mine and drove to work like that once and it sounded sick but it did stall 3-4 times or so as the idle got pretty low. I am pondering the turbo xs 50/50 but have not found a video of that to hear what that sounds like, at least a good driving video. I like it loud as s***!