As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WITH ENGINE ANTI ICE OFF RT ENGINE COWL VALVE OPEN FLICKERS ON AND OFF. GROUNDED - YES. FOUND CANNON PLUG LOOSE TO TAI VALVE ON #2 ENG. REMOVED CANNON PLUG, INSPECTED, REINSTALLED CANNON PLUG, PERFORMED ENG RUN AND OPERATIONAL TEST GOOD. REF: B737-800 AMM CH. 30-20-710-801.