Thanks for the answers. I was intending to return to the OE return under the kidney box and breathe from both the exhaust side which currently has a bung which has the knock sensor wiring attached, and the original hole that has the kidney box attached. The real question I was asking which is probably answered by Martin and Tosh was whether I could make all these connections without disassembling the engine at all (manifolds etc) as it looks very difficult to get in there to connect the hoses. Another question is why do these breather catch tanks vent to atmosphere and not feed back into the intake after separation of the oil and vapour. Assume you would need too still use some sort of PCV valve if you wanted to do this. Thanks again. David.