As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DISCREPANCY: DUCT PRESSURE GAUGE INDICATES 15 PSI DIFFERENCE BETWEEN RIGHT AND LEFT. RIGHT IS 15 PSI LESS THAN LEFT AT TAKEOFF AND CLIMB POWER. CORRECTIVE ACTION: REMOVED AND REPLACED RH PRSOV IAW AMM 36-11-09. OPS CHECK GROUND CHECK ETOPS VERIFICATON OK.