I purchased this wideband O2 sensor to go with my F/I setup in my E46 M3. I chose this system since it was simple to operate, and the O2 sensor can replace the stock sensor so I don't have to install an extra bung in the exhaust manifold (it has both wideband and narrow band output). All of my research says that it should work (as far as replacing my stock O2 sensor). I know E36 guys have had success with this setup, but I was wondering if anybody with an E46 M3 has done the same.

I tried using AEM 30-4100 Wideband kit, adjusted to narrow band output, when i feed it to my ecu. It runs horribly. and when i checked the voltage, it sometimes spikes to 1.5 to even 2 volts sometimes. During idle the gauge shows 17:1 a/f ratio but the voltage output was fluctuating +/- 0.5 volts. So my conclusion is it seems like it added voltage from my narrow band with my wideband (although the only wire feeding the ecu is being cut of and connected to the output of the wideband).