2003 BMW 330ci • 6 cylinder 2WD Automatic • 91,000 miles

03 bmw 330ci back firing and missing
p0300 random missfire
p0313 low rpm missfire
p0171 and p0174 left and right banks lean
November 27, 2010.

Lean fuel condition could be caused by one of the following below: 1. Vacuum leaks
2. EGR and PCV valve.
3. Low fuel pressure.
4. Dirty fuel injectors.
5. Mass Air Flow Sensor.
6. Oxygen Sensor.

Nov 27, 2010.
No vacuum leaks, fuel pressure good, my scanner does not support european so can not get anything on mass air flow and bmw does not use egr they us A.I.R

To find the root cause may require having BMW specific scanning equipment. What method did you employ to assure there are no vacuum leaks? What was the fuel pressure? Has the engine had cam timing checked? More history and a more detailed story of what has been done and how the car showed up at your shop might shed some light and would go a long way in our being able to help, otherwise we are in the dark here.

Dr. Hagerty
Nov 27, 2010.
Also, what coils are in the engine? The 2003 cars had lots of coil issues, pull one and describe it to me please, what color is it, is it Bosch or Bremi?

Dr. Hagerty
Nov 27, 2010.