As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL330 CAB ALT 8900 AN D CLIMBING. DIFF PRES 6.6 VERIFIED CORRECT PART NUMBERS INSTALLED PER IPC 21-25-17-050-941A-D: LOWER RECIRCULATION FAN ITEM 640 P/N 7010911H03S06, OUTER DUCT ITEM 635 P/N 7010046H01 REF LOG # 3928832 FOR REPLACEMENT OF R/H LWR RECIRCULATION FAN AND RECIRCULATION INNER DUCT, SLEEVE''S AND COUPLING.