As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - CREW REPORTED SIGNFICANT ENGINE PRESSURE RATIO SPLIT THAT BECAME WORSE AS ALTITUDE INCREASED. EMERGENCY DECLARED FLIGHT RETURNED DFW LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED NUMBER 1 ENGINE PT2 BULLET. SYSTEM GROUND CHECK NORMAL OPERATION.