2 Big issues all the codes are showing errors and then not showing errors and then they’ll show errors again sporadically after being cleared the second big problem I’m having is oil pressure dropping while at idle After LS 2 rebuild how do I rule out ECM or PCM or fuse box failure? Or could it be both? Oil pressure also dropping when my foot is off gas not giving any throttle during test drive after the rebuild… If I’m getting the correct information on my gauges and it has in one of the codes “lost communications” with I’ve already replaced ignition replaced the power control relay and all fuses , replaced the starter relay and still both of those are coming up in my OBD reader. is there anyway to narrow down more specific problem within the OBD reader in classification and which test would that be. both are still coming up bad sporadically. do I need to get the multimeter out and how would I go about using that to trace down the wiring issue. I know this is a lot and I appreciate all inputs given any kind of experience is extremely appreciated Oh and I have installed. a high-volume melling oil pump. could it be the oil pump? Or O-ring or O-ring what is the process of elimination without Having to take the motor out or purchase more parts?