As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DUCT PRESSURE SPLIT AT CRUISE L38 R9 C/B P6-4 B7 WAS OUT. GROUNDED-YES. DUE TO HISTORY REPLACED NR 2 ENGINE BLEED AIR REGULATOR, REF B737-900 AMM 36-11-03-400-801. RESET C/B P6-47. PERFORMED IDLE RUN RT PSI 10 WITH 1 PACK RT PSI 40. ACCOMPLISHED ENGINE BLEED AIR CROSSOVER OPERATIONAL TEST, REF T/C NG-36WC-00001. BLEED AIR PSI WITHIN LIMITS FROM IDLE TO 80% AT N1, REF AMM 36-11-00-710-801. CIRCUIT BREAKER AT P6-4 B7, NORMAL NO DEFECTS.