S8ER95Z

Ok, I popped my hood tonight after noticing the dash flickering at idle. The drivers side didnt show any signs of arcing or anything..however all 4 plugs on the passenger side have arcing going on!!! WHY?? Im confused..I wired everything away from the headers and nothing is touching... do I need die electric grease to stop this issue?? the plugs not working?? Something is a miss here (parden the pun). Any suggestions?