on modern engines it is simply no longer the case where you can just open up injectors/disconnect plug leads and listen to changes in engine firing cycles and can actually cause damage but my advice is to get it onto a suitable code reader where you can shut down each injector in turn safely to determine which cylinder is causing your mis fire,it may not be injector related but at least it narrows down your search and pinpoints where to start your investigation.
cdc
May 2013