As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMBOUT NR 1 EGT DROPPED TO APPROX 530 WITH MCT POWER SET (88.7 PERCENT N1) AND REMAINED THERE UNTIL THROTTLES PULLED BACK. TEMP WAS ALSO FLUCTUATING +/-30 ALL OTHER ENGINE PARAMETERS WERE NORMAL. FOUND FIREWALL CONNECTOR AND SUMMING PLUG LOOSE. CLEANED AND TIGHTENED CONNECTORS. RANG OUT LT AND RT EGT HARNESSES AND EGT JUMPER. NO FAULTS FOUND. OPS OK ON ENGINE RUN.