I have a 2004 Road King that has running right since I purchased it 4 years ago. But after the 15000 miles service the engine began to runs rough and sometimes quits, especially at when cold (its an EFI).....the best way I can describe the sound at idle is as if a long duration race cam had been installed in a car engine. The bike seems to run fine at high speeds. I performed a diagnostics and came back with an error code 1356 Rear Combustion Cylinder. Any suggestions?? Thanks. Tony