Very strange symptoms, rough at all low and high rpm.
Regarding a bmw e46 318i 1.9 m43, from 2000.)
I have been having hard time troubleshooting a moderate inconsistency in rpm at low as well as high engine speed.
Rpm are slightly and equally unstable(Within 2 or 300 rpm) at any engine speed, as Long as the engine is not put under any load(not in gear).
I also have check engine light which reads p0170 code
Btw I have been thought and changed pretty much all air/vacuum hoses.
Hope u guys would be so kind and give your opinion on the symptoms
Best regards Patrick