As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SAME ISSUE AS LO 60259389 +/-3 PSI DUCT PRESSURE OSCILLATION AND CABIN RATIO OSCILLATION +/-3. GROUNDED - YES. C/W PACK FLOW TEMPERATURE CONTROLLER BITE REF B737-900 AMM 21-61-00-740-801-002, NO EXISTING FAULTS FOUND, HISTORY SHOWS FLOW CONTROL VALVE FAULT # 21-51253. NO HARD FAULTS NOTED. REPLACED RIGHT PACK FLOW SENSOR PER AMM 21-51-43, OPS AND LEAK CHECK OK. REMOVED AND REPLACED RIGHT FLOW CONTROL AND SHUTOFF VALVE PER AMM 21-51-01-000-807-003 / 21-51-01-400-806-003. OPS CHECKED AND LEAK CHECKED GOOD.