As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB OUT AT CLIMB POWER LT DUCT PRESS AT 15 RT DUCT PRESS 40. NO EICAS MSG ONLY PRESS DIFFERENTIAL BETWEEN SYSTEMS. REPLACED AIR SUPPLY PRESSURE REGULATING AND SHUTOFF VALVE. (PRSOV) IAW AMM 36-11-09-002. RAN BOTH ENGINES AT HI POWER, OPS CHECK GOOD, NO DEFECTS NOTED. OK FOR SERVICE.