The Air Force is making changes as part of an ongoing attempt to fix the hypoxia problems.
And now restrictions put on the plane are going to be lifted.
Today, the Pentagon said they've identified two things in the F-22's life-support system that they need to correct.
The first is replacing a valve on the vest worn by pilots.
The second problem involves increasing the airflow to pilots by removing a filter.
It was designed to detect contaminants in the oxygen system.
The Air Force says they're also looking to improve the oxygen-delivery hose and its connections.
The Air Force hasn't been using the vests since June, but two pilots had hypoxia-like problems even without the vests.
The Pentagon says the flight restrictions will be lifted in phases as they see how pilots react to the changes.
Defense Secretary Leon Panetta has already approved deploying a squadron of F-22s to an Air Force base in Japan.
No word yet on when they are leaving.