2007 mini cooper

Description

[This is a mechanic special. I have had the head checked, the valves done, new spark plugs,new ignition coils, compression tested,changed the fuel rail,new oil pump,new water pump, new oil sensor, new thermostat,etc, etc. and it has a check engine light on still and stalls at low idle. The code is a misfire in cylinder 3. I don't know what else to do. After all this work I hope someone can get it running good