As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PSM - FLT 3580 - LEFT EGT ERRATIC INITIALLY PLUS OR MINUS 50 TO 60 DEGREES, THEN PLUS 100 DEGREES. DROPPED TO 150 DEGREES (SRL OFF) ALL OTHER ENGINE INDICATIONS NORMAL. REMOVED AND REPLACED MONOPOLE, DID NOT CORRECT THE PROBLEM. REPLACED DELTA P CONTROL UNIT. OPERATIONALLY CHECKED NORMAL. (M)