could be any number of things...VANOS solenoids, misfires, etc. now with the code eraser turned off it should only be a matter of time before it comes up again. update us then.
EDIT: drawings are funny by the way!
Cobb E40 PROtune by Jake@PTF/RR catless DPs/aFe DCI/ETS 5" FMIC/ER CP/Forge DVs/Alpina B3 TCU flash/BMW Perf. Exhaust./BMW Performance Style 313s/M-Tech Rear