Will your tune tell you what cylinder or cylinders are misfiring through a Log? Most of the time its plugs, coils, injectors or a combo. If you can read the missing cylinder swap the coil with another one not having a problem to see if the issue moves with it. If it moves its the coil if not it could be the plugs or injectors.
In the case of the 335 with a tune after about 25K miles the plugs are history.
Last edited by bear-avhistory; 11-15-2012 at 03:25 PM.