BMW Repair: Cold Idle, vacuum hoses, sensor circuit

Question
Every first(cold) start of the day of my 1995 740i my idle is extremely poor (the almost dies). Check engine light comes on, codes indicated O2 sensor which I replaced (no effect), cleaned idle cotrol valve, checked vacuum hoses. When the car runs for 10-15 minutes everything becomes normal and check eng. light goes off, idle becomes perfect. Should I reset codes by grounding pin #7 in OBD connection after replacing electric parts. What else could it be, what steps do you recommend?
Thank you.

Answer
This is a common problem with the cars` this day and age.Although you checked the code and found there was a fault in the o2 sensor circuit it does not mean the sensor is at fault(as you found out).Reseting using pin#7 only resets the service indicator/oil service lights.
I think going further into the code that you recieved,rather then just replacing the part is what you need to do.What was the code number orfurther information of the code that you got would be helpful.
Check the therottle plates for clearance and cleaning