Need help with 02 runner

My son has an 02 4runner. He is trying to pass emissions and needed to replace the O2 sensors. After replacing the O2's he drove the runner around for a day and attempted to take the emissions test. Test came back, 2 of the 3 systems were ready, but the 3rd was registering "not ready". So he drove a while longer and has tried to retest, and now all 3 systems are registering "not ready".

There are no codes being thrown, but since the system is saying "not ready" he cannot pass.

Has anyone else seen this? Not sure where to go with this to resolve it. He has put over 280 miles since changing the O2 sensors and still had the "not ready" on the computer.

 

Try disconnecting the negative battery terminal for 15 minutes,

 

Follow these steps

Toyota TSB on completing monitors:
https://www.toyotaparts.metro-toyota.com/READINESS_MONITOR_DRIVE_PATTERNS_T-EG02-003.pdf

Other option:
https://www.smogtips.com/smog-question/2664/Toyota-4Runner-Drive-Cycle-to-Set-Emission-Monitors