MECH INSTALLS OXYGEN REGULATOR. IT IS WRONG PART; ORDERED BY DAYSHIFT MECH.

Narrative

I'M CURRENTLY AN ACFT MECH WITH ACR IN EWR. I RECENTLY WAS DISPATCHED AT XY00 TO ASSIST DAYSHIFT MECHS IN THE REPLACEMENT OF A CAPT OXYGEN DEMAND REGULATOR ON AN ACFT WHICH WAS IN DELAY. I ARRIVED AND THE ACFT REGULATOR; PART NUMBER 28000.17; WAS ALREADY REMOVED. THE MECH WAS AWAITING THE NEW REGULATOR; WHICH HAD ALREADY BEEN ORDERED BY DAYSHIFT. SHIFT CHANGE WAS AT XY30; SO THEY TURNED THE NEW PART OVER TO ME. I INSTALLED THE PART; PERFORMED THE SYS TEST PER MAINT MANUAL 35-11-41 AND SIGNED OFF THE LOGBOOK. I WAS CONTACTED THAT SAME NIGHT WITH A POSSIBLE PROB FROM THE INSTALLATION. I RESEARCHED THE PART I INSTALLED AND FOUND THE PART WAS THE WRONG EFFECTIVITY. THE PART WAS ORDERED BY DAYSHIFT BUT I INSTALLED THE PART AND SIGNED THE LOGBOOK. BOTH THE PART DAYSHIFT REMOVED AND THE PART I INSTALLED WERE THE WRONG EFFECTIVITY FOR THIS ACFT; AND NO ONE KNEW THIS AT THE TIME OF INSTALLATION. I THOUGHT THE PART HAD BEEN RESEARCHED BY DAYSHIFT. IN SHORT; ANY JOBS I'M ASSIGNED TO WHEN REPLACING PARTS WILL HAVE TO BE VERIFIED TO AVOID ANY FUTURE MISHAPS.