its got to be leaking the oil for it to drop that much so fast. the oil pressure sensor near the oil filter would be my first check. it leaks out the plug on it. can be a slow drip to a steady stream or oil coming out.
that looks to be a head gasket out the tail pipe. its sure running rough. it almost sounds like the plug wires are routed wrong.
double check the new wires. someone may have moved the coils around and the numbers no longer in the right place.
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