As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ATB, AIR SYS L PRESS LO INDICATION IN CLIMB OUT ( PRESSURE REGULATOR AND SHUTOFF VALVE (PR ). REMOVED AND REPLACED LEFT ENGINE PRSOV PILOT VLV PER AMM 36-12-03. OPS CHECK GOOD. DURING ENGINE GROUND RUN RETURNED ACFT TO NORMAL OPERATING STATUS REMOVED PLACARD AND UPDATED MIC SHEET OFF: PN: 3399156-4 SN: 408 ON: PN: 3399156-5 SN: 259