Hi
My car yesterday started misfiring like crazy all of a sudden. Cylinders 1,2,3 are all misfiring.
I have had my spark plugs changed only 6000 miles ago.
My OBD reader says the fuel rail pressure is OK.
Any Ideas?

 

Check the ignition coils. There is a coil on each plug. My 2007 R56 suddenly showed misfire on Cyl 1. Turned out it was a bad coil, changed the coil, running fine.

Check it out here:

 

Mine started doing it yesterday, cylinder 2 only. It wasn't throwing a code till it did it and I kept the accelerator to the floor. If I backed out of it, no code. When I stayed in it, it continued to miss then threw a code and went into limp mode. Checked the codes and cylinder #2 showed.

 

Update,
Swapped cylinder 1 & 2 coils and the misfire followed the bad coil. Replaced the coils this weekend, car runs great again! New plugs finally arrive today so perhaps next oil change, I will replace the plugs.

 

I had several multiple misfires (random) and so far it looks the Diverter Valve was the problem( S R56 model). If bad, avoids the extra boost to be returned to the compressor inlet, affecting the air/fuel mixture giving misfire codes and putting the car in a kind of "safe mode" with 4000 rpm limit. No engine light.

 

If the misfires are all cylinders, and there is a code relating to timing, might want to check when the timing chain was done.