E46 M3 cannot pass emissions test because of "not ready" sensors

I have a 2006 M3 with 107K miles, and I live in Illinois. I cannot get my car to pass the Illinois emissions test because the sensors - specifically, the catalytic converter sensor - reads "not ready." I had repeatedly driven the car as recommended by BMW to get the sensors to "ready" status, but nothing has worked. I have let the mechanics at my BMW dealer - Knauz of Lake Bluff - drive the car for a week, and they could not get the sensors to "ready" status either.
I have spent more than the $450 I thought that Illinois required to get a waiver for the emissions test, but that has not worked either, since the Illinois Air Team has told me I can only get a waiver if my car fails the emissions test, and "not ready" sensors do not qualify as "failures."
Any suggestions would be much appreciated!