To be perfectly honest, 1.8T engines were never designed to have BOV on them, so my suggestion would be take it off, reinstall the original Bosch valve or a Forge 007 DV and sell the splitr. I have one on my 1.8T and had exactly the same problems, to be honest, it needs to be setup on VAGCOM and monitored properly to see if you are actually encountering problems or not.