Be careful in snatching,snapping, yanking or jerking the injectors free. This is not a simple bolt in an infinitely strong block of material.
The injector is a lot stronger than the socket.
Using an air driver will work until you come across a n injector that has carbon up the threads, and then it will[may] strip the threads.
These issues show up as the freed injector immediately gets harder to turn again.
Do it manually. to and fro with solvent fluid. .
If they have not been out for a long time , use a penetrating fluid.
If you don't have a 'T' bar with extensions, use a breaker bar with two long extensions to the socket. this will give some sloppyness.
Best practice:
If you use a universal joint as first adapter on the injector socket you will all but remove any stray leverage and pass on near pure torque.