appartently when the fuel pressure isn't high enough in the line the impreza ecu runs in a safe mode. does anyone know what this exactly is and how it affects your engine running as mine still isn't going

 

It can happen for several reasons, when there is some fault the ECU picks up.

It puts the car into a "safe" mode, limp home mode, to save the engine ( so I guess it is not a critical error or failure like holed piston or thrown rod ) and reduces the boost ( 5 psi ish ) and other agressive characteristics that could harm the engine.

Fix the problem, reset ECU (?) and all is well.

Think I got that right, but more knowledgable people on here who will correct me!

 

Well the problem I have at the moment is a missfire which is causing the engine not to run. Traced it back to the output from the ECU, the diagnostic check has come up clear, so presume it could be something to do with this safe mode.
Cheers