What was found
#2 ENGINE LOW OIL PRESSURE INDICATION AT CRUISE. REDUCED POWER BY 5% N1 AND OIL PRESSURE CAME BACK IN THE GREEN. PRECAUTIONARY DIVERT TO PHX AND DECLARED EMERGENCY. ENGINE WAS NOT SHUTDOWN INFLIGHT. ORIGINAL ROUTING DAL-LAS. UPON INSPECTION BY TECHNICIAN IN PHX, IT WAS REVEALED THE OIL CAP WAS UNSECURE ON #2 ENGINE, RESULTING IN LOSS OF 3 QTS OF OIL. OIL RESERVOIR WAS NOT EMPTY. MX INSPECTED, CLEANED, SERVICED, PERFORMED ENGINE POWER RUNS WITH CREW AND NO FURTHER DISCREPANCIES.