Do you mean knock sensors? If so, yes. I am not sure, but usually the sensor would be bolted to the intake side of the cylinder heads. I would guess there are four of them. A quick check of ETK or RealOEM would probably answer your question. If you mean nox sensors, never heard of that used on a BMW.


Update: I just checked RealOEM. There are two knock (ping) sensor parts. Each part has two sensors, so a total of four sensors.