What was found
IN APR AND NAV MODE, AUTOPILOT WILL NOT PROPERLY INTERCEPT AND TRACK LOCALIZER AND/OR VOR SIGNAL. AUTOPILOT WILL SCALLOP ACROSS COURSE. AUTOPILOT HAS BEEN SENT IN FOR EVALUATION. WE HAVE EVALUATED OUR PN-101 HSI TO DETERMINE IF THEY ARE THE SOURCE. AFTER EVALUATIONS THE AUTOPILOT IS SOURCE OF THE PROBLEM. ALSO, WHEN FLAPS AND GEAR ARE EXTENDED ON APPROACH, AUTOPILOT WILL PITCH UP AND DOWN WILDLY. THIS PROBLEM HAS PERSISTED SINCE INSTALLATION AND ON-SITE EVALUATION. AWARE OF SEVERAL OTHER AIRCRAFT THAT HAVE THIS PROBLEM. AUTOPILOT NEEDS TO BE FULLY RE-EVALUATED BY THE FAA AND MANUFACTURER.