As I said last time, although the broken catalytic convertor had been replaced, the engine still had some sort of misfire and engine fault. Since I've had the Mini, it's been a battle to get it back up to scratch, lurching from one problem to the next, but slowly and surely they were being addressed.
A previous visit to the friendly chaps at Mintech in Bury had found some sort of air leak from around the head, so it was initially thought that the inlet manifold gasket was the cause. And at a more recent visit, Martin, the mechanic, showed me a split pipe that connects the intercooler and brake vacuum pipe - which would also explain why the brakes weren't working as effectively as the should have been.
After finally getting booked in a few days later it didn't take Martin long to diagnose the problem - and a fairly simple one at that. After all the fuss and problems, it turned out to be a some loose nuts on the inlet manifold, allowing lots more air to be sucked in to the engine and ruining performance.
A few turns of the socket and the nuts were all tight again and the air leak was gone. But as we know, things are never just as easy as that for me...
Diagnostic at Lohen