This meassage comes from downunder (Australia). I have a prob with this scooby-doo. Variably it hesitates & surges from 2500 rpm upwards and it does not do it all the time, suspecting plugs/leads these were changed to no avail. Some research was done into the O2 sensor I disconnected and took it for a run no different about the same power, hesitation & surges etc. Re-connected it and it was much better but still not as good as it should be. I would be greatful for any ideas. I am now suspecting dirty injectors can anybody point me toward documentation explaining the process of removal of the injectors methods, processes, procedures and gotchas ect.

Have a look at the airflow sensor. Your problem sounds familiar. It can be cleaned,gently, or replacedcheaply[for subaru].It's quite a common fault on these engines, so worth a try.