Originally Posted by ScottSpeed21

Thanks, I do realize how MAF sensors work. But realize that the 4B11 does also have a MAP sensor that reads the boost pressure in the intake manifold which helps adjust fueling and timing accordingly. A VTA valve on this MAF and MAP equipped engine doesn't result in the issues that the solely MAF metered engines had.

People have issues with aftermarket BOVs because they don't realize their stock valve leaked and the new valve doesn't. Without being tuned for the new valve, the engine gets more air and boost pressure than it's providing fuel for which can lead to excessive knock or limp modes from hitting the airflow limits.

I've been running a VTA BOV for a year and half, daily driven, and I've had zero issues whatsoever, regardless of which tune has been flashed to the ECU. No fat rich conditions during gear shifts, no stalling at all, no jerky driving....nothing, not a single issue or problem. The car still runs and drives as smooth as it did the day I drove it off the lot. Currently I have the Tial 50mm. It cleans up the engine bay nicely, improves spool up and will hold all the boost pressure I ever throw at it without leaking.