Air carrier technician reported they replaced the number two engine IDG oil seals on a B737. They were informed the aircraft had to divert due to low oil pressure on the number two engine.

Narrative

I was assigned to work on aircraft X with 2 of my coworkers. Engine 2 IDG (Integrated Drive Generator) sealol replacement. We removed and replaced engine 2 IDG sealol IAW (In Accordance With) AMM (Aircraft Maintenance Manual) XX-XX-XX-XXX-XXX-XXX and XX-XX-XX-XXX-XXX-XXX. The required engine 2 idle power leak check and high-power assurance runs were completed with no leaks found at the time as witnessed by myself and my coworkers. Aircraft was then returned to service. I was made aware that the aircraft had to divert during a flight to ZZZ1 for low oil/ pressure on engine 2. I was also made aware that an o ring may have been missing on the IDG sealol we replaced. My coworkers and I installed all the correct parts and o rings in the correct way as required using the AIPC (Aircraft Illustrated Parts Catalog) and AMM references. Part numbers installed are noted on the log page. For the record I am stating that when the required leak checks were performed that there were no leaks found after parts were replaced from IDG sealol. My coworkers and myself are very conscientious of our work as professional mechanics.