My Plus8 with Gems management used to get the light on. I have an Autel Maxiscan OBD and it showed the fault as random intermittent misfire. Reset using the Maxiscan. After a check of plugs, wiring, connections I tried VPower petrol. That worked. I try to stick to it but use 95 octane as well. It looks like the refuel/95 octane/restart as described above can cause it to recur, indicating a cooled sensor possibly triggering it. The Maxiscan is now a few years old so updates are not supported my Autel. I did try it once on an S1Aero and it didn’t register. That may have been my fault in not clearing old data out of it first before selecting BMW option.
I recently put heat shield round the cats so will see if that helps. Trouble is it is a case of waiting to see what happens.
