the Trionic 7 software compensates for the loss of air that is being released causing you to run very rich and also throw codes as it sees it as a air leak. you can do a search as this has been discussed many many times...I know we need a recerculating style valve.
My question is why???
How does it know it's being vented to atmosphere and not back into the intake? Or visa/versa....
I have a phew BOVs on the shelf that dump to atmousphere and kinda wish I could fit one.