As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
JFK (REPEAT ITEM) CREW REPORTED EICAS MESSAGE "LEFT ENGINE PRESSURE REGULATING VALVE AND LEFT BLEED ANNUNCIATOR". EMERGENCY DECLARED FLIGHT RETURNED JFK LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED LEFT ENGINE PRESSURE REGULATING VALVE CONTROLLER. SYSTEM GROUND CHECK NORMAL OPERATION.