As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMB OUT, RECEIVED LT ENGINE OIL MSG ENG OIL AURAL AND LT ENGINE OIL INDICATION LESS THAN 20 PSI. COMPLIED WITH QRH SHUT ENGINE DOWN RETURNED TO DEN, FLT 5721. REPLACED LEFT ENGINE EXHAUST FRAME AND CARBON SEALS. ENGINE RUN/LEAK CHECK GOOD. OIL CONSUMPTION CHECK GOOD.