For all the people still having oxy sensor and EGT codes, you should change your vanos camgears bolts.
You need the following parts to do it:
Part number for the bolts (x12): 07129905536
http://www.ecstuning.com/BMW-Z4-M_Ro...nos/ES2130382/
Vanos filter change kit.
loclite.
I had all 6 bolts loose on the intake side, this was messing up the timing and causing all these gremlins. After i have put everything back together and drove the car 200 miles, i feel like i have never driven the car like this ever since i bought it. it pulls like a fucking train, the extra torque in the whole RPM range is brutal and with the diablos it howls above 5K RPM, literally it howls.
btw i have afe intake, EURO headers, diablo exhaust (and a little trick my mechanic performed on my vanos without telling me which is to increase the fuel ratio a small 2% on 3-4K RPM)
in other words, this tune made the car feel, drive and act like a race car.