Temporary MIL lamp illumination and juddering without any codes being logged = low battery charge.
- just in case you don't get a fault code.
As for the alleged EFI unreliability... I've just returned home this evening from a combined Land's End to John O'Groats and North coast 500 run the majority of the 2,421 miles of which were travelled were in pouring rain. No Mil codes and no problems whatsoever, nor did the EFI get blown off it's manifold or the electronic ignition fail and all with an average fuel consumption of just under 99 MPG. An absolutely enjoyable and comfortable experience on a bog standard B5 EFI (apart from rack and top box)
The only maintenance was to put a little air in the tyres to compensate for the wide variance in ambient temperature between South and North and to adjust the chain by 1 notch on the snail cams. No determinable amount of oil was consumed either nor anything found dripping from or obstructing the breather pipe