Well you can't feel any sort of power increase, and there's no change in sound, it's like driving my old DA9 but a bit more powerful and higher revving. Like it used to have quite a significant change in sound especially considering the intake is open air (no top of airbox). But now nothing..? I don't understand how it works one day, then fails overnight while it's sitting there and doesn't work the next day..?

(Please excuse my frustration)

Which vacuum line might this be cause I'm pretty sure they're all hooked up fine?

No I haven't gone as far as to pull the valve cover off yet, I don't think it's a serious mechanical failure so I'm gonna save checking that type of stuff till last.

Thank you for your advice I will definitely keep these things in mind! Anyone else got any idea's?