As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN)AFTER TOUCHDOWN WHEN REVERSE THRUST WAS SELECTED THE #1 THROTTLE STUCK ON THE IDLE GATE AND THE REVERSER WOULD NOT ENGAGE. MAINTENANCE FOUND THE THRUST CONTROL SYSTEM DIRECTIONAL VALVE VERY STIFF. AFTER VALVE REPLACEMENT THE SYSTEM FUNCTIONED NORMALLY.