As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX - ON FLIGHT 2168, RETURNED TO GATE, NR 1 ENGINE OIL PRESSURE 53 PSI ON GROUND WITH POWER LEVERS AT FLIGHT IDLE NH 80 PERCENT. MAINTENANCE REMOVED AND REPLACED NR 1 ENGINE OIL PRESSURE TEMP GAUGE. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.