As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED. EMERGENCY DECLARED. JFK-CDG FLIGHT RETURNED TO JFK ACCOUNT LEFT HAND ENGINE OIL PRESSURE INDICATION. OVERWEIGHT LANDING UNEVENTFUL. OIL TANK FILLER CAP LEAKING. REMOVED AND REPLACED CAP SEAL IAW AMM 79-11-03 (AALA20170428008) AND OIL TANK PRESSURIZING VALVE IAW AMM 79-11-02. LEAK AND OPERATIONAL CHECK GOOD.