Carb conversion NCT

[lod_]

Sorry if I'm doing this wrong, long time lurker, first time poster!

I converted my 99 mpi mini to a carb setup over the summer in the UK, and am having a nightmare with the NCT. I falsely assumed that it would be tested to the engine specs (as per MOT), and not the reg, but it's just been confirmed that it will be tested by the reg with no exceptions.

I'm completely stumped as to what to do next. I was just wondering if anyone had any advice? I managed to lean it off enough for the idle, but it still blew 3% for high idle. Thanks for reading.