What was found
APPROX 5 MINS AFTER T/O THE RT ENG EEC AND A/T INOP EICAS MSG'S WERE DISPLAYED W/CORRESPONDING HIGH EPR. COMPLIED W/QRH PROC'S-REF TO MEL FOR POSSIBLE CONSIDERATIONS. THE STBY & NORMAL INSTRUMENTS DISPLAYED THE SAME DATA W/THROTTLE ADJUSTMENTS. WHEN THE RT THROTTLE WAS ADVANCED THE EPR WOULD CONTINUE TO CLIMB WHILE THE EGT/FF WOULD FINALLY TAPER BACK DOWN SHOWING THAT THE ENG LIMITER WAS WORKING. ONCE ON DECK-ALL RT ENG INSTRUMENTS RETURNED TO NORMAL. ACFT HAD A 2ND AIR TURN BACK AFTER REPLACING THE RT EEC, EPR TRANSMITTER, HIGH VOLT ISOLATION MODULE, WITH A SATISFACTORY HIGH POWER RUN. R&R P1 PROBE TUBE ASSY PER MM 20-10-09-4 AND R&R THE P1 AIR ACCUMULATOR PER MM 77-11-02-4-0. RAN ENG PER JRH AT VARIOUS POWER SETTINGS AND VERIFIED EPR INDICATIONS WERE NORMAL AT ALL POWER SETTINGS PER MM 71-00-00-5-3. OK FOR SERVICE.