What was found
(AIRCRAFT NOT GROUNDED) (EMERGENCY DECLARED) CAB PRESS EXCESS CAB ALT AT CRUISE. / REMOVED AND REPLACED PRESS CONT 2 (12HL) REF. AMM 21-31-34-000-001 AND REF. AMM 21-31-34-400-001. REMOVED AND REPLACED OUTFLOW VALVE (10HL) REF. AMM 21-31-51-000-001 AND REF. AMM 21-31-51-400-001 OR REF. AMM 21-31-51-000-006 AND REF. AMM 21-31-51-400-006 (W/O: 543749, TASKCARD: NR-00001). THIS CLEARS MEL 21-31-01C, MDDR# 226779, INOP STICKER REMOVED, M-ACTION REVERSED.