As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SIGNIFICANT DUCT PRESSURE DIFFERENCE BETWEEN LEFT AND RIGHT. AT 91% N1 DURING CRUISE FLT. LEFT DUCT AT 37 AND RIGHT 9. PERFORMED FIM 36-10 FT 838, REMOVED AND REPLACED PRSOV IAW AMM 36-11-09/501, AND PRVC IAW AMM 36-11-18/501, BOTH OPS TEST NORMAL ON ENGINE RUN UPS.