As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EN ROUTE LIM-DFW AT CRUISE, SMOKE DEVELOPED IN THE AIRCRAFT. RECEIVED EICAS LOW OIL PRESSURE FOR LT ENGINE. OIL QUANTITY DECREASED RAPIDLY. EMERGENCY DECLARED AND RETURNED TO LIM WITHOUT FURTHER INCIDENT. REPLACED LEFT ENGINE. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)