As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT OIL PRESSURE LIGHT ILLUMINATED CLIMBING THROUGH 16,500 FEET. FOLLOWED QRH PROCEDURES RETURNED BACK TO SBA. LIGHT EXTINGUISH THEREAFTER. INSPECTED LEFT ENGINE, SERVICED ENGINE OIL, CLEANED CANNON PLUG ON OIL PRESS SWITCH AND RAN ENGINE AT 100 PERCENT TORQUE FOR 15 MINUTES. ALL CHECKS GOOD.