As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT IDLE, RIGHT DUCT PRESSURE FLUCTUATED BETWEEN 7 PSI AND 10 PSI. GROUNDED - YES. REPLACED HIGH STAGE VALVE PER B737-900 AMM 36-11-06. REMOVED AND REPLACED #2 ENG HIGH STAGE REGULATOR REF AMM 36-11-07 VERIFIED #2 ENG DUCT PRESSURE WITHIN LIMITS REF AMM 36-11-00-710-801. RESTORED HIGH STAGE VALVE #2 ENGINE REF AMM 36-00-00-440-805.