Q: Rough idling misfire & a thumping sound from the front of engine

Hello. It sounds like your cam timing may still be off or there may be another issue. I would typically do a compression test first. If the compression is low on only a couple of cylinders, then you have an internal engine problem. If it was low on all cylinders, then you have a timing issue and need to recheck the recent work that was done. If the compression is fine, then you have another issue which may be related to ignition timing or you may simply have a coil or injector issue. These parts would have to be tested separately to isolate the cause of your rough idling issue. A thorough diagnosis of the Check Engine Light code and relevant systems will also help to pinpoint the problem.