Check the Fuel Pressure
On Subaru vehicles, it’s easy to check the fuel pressure
before and after the underhood filter. Most models specify
a fuel pump output flow pressure of 43.5 psi (an exception
is the 1992-1997 SVX, for which the spec is 36.3 psi).
Pressures lower than specified before the filter means
there’s a problem with the pump, tank pick-up or fuel
supply lines.A pressure drop at the output end of the filter
indicates a restricted filter. Remember; if you have a
clogged filter, there is a good chance that you have a
problem in the fuel tank, too, in the form of either an
accumulation of rust or dirt, a contaminated pick-up sock,
or both.


Removing a fuel injector.
They are oh-so delicate but I have managed to yank a fuel injector
with a lot of patience.
First, relieve the fuel pressure in the line.
Second, squirt some penetrating lubricant around the perimiter of the
injector body and let it soak for a bit (probably does no good but
makes me think that the o-ring has less of a chance of damage)
Then find a pair of pliers that will allow applying pressure to each
side of the injector (where the arrows point on the picture i've
doctored up).  If you can use pliers that will also protude into the
indent on each side of the injector, all the better.
You can either pull STRAIGHT up on the injector or, while applying
gentle pressure, pry up evenly on both sides of the pliers using the
injector cap screw mounting surface as a leverage point.  If your
pliers start to slip, just stop, congratulate yourself on giving it a
good try,  and remove the fuel rail instead.
When reinstalling, use some grease on the o-ring to simplify proper insertion.

These things are very expensive so use a lot of caution.

Have provided some pics in the folder below to give you an idea of
where to apply pressure and what a removed injector looks like.