As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN CRUISE, AUTOPILOT NAV/LOC WANDERS LT & RT OF COURSE MORE THAN A MILE, MANUAL CORRECTION NEEDED TO HOLD COURSE. TRANSFERRED ITEM TO DEFERRAL AUTOPILOT VOR.LOC MODE PER MEL 22-1-7. PLACARD INSTALLED. REPLACED NR 1 NAV RECEIVER. A/P SYS OPS NORMAL ON GROUND IAW MM 20-00.