You failed your MOT and have an advisory Oi Mr Lancer,
We do not say rubbish if the person already has the item, if he/she does already have the item then we say that it is not recommended!!!!
There are many turbo cars running on the bleed valves that have no issues. Granted, the majority of them are branded ones (that may have been professionally installed) and not the "R" or "Super" type ones that ebayers have listed like the plague which R the ones to avoid like the plague as they are prone to over boosting the turbo which makes the engine go POP!!!!
You will need to get trained up a little buddy, I think you need to add my suggestion to your ADVISORY LIST!!!
El