My daughter's 1993 s/wagon occasionally loses power progressively, motor stutters and comes to a complete stop. Turning off and sitting 10 miniutes all is fine and it will run for days, weeks or months before it again mysteriously dies. Any ideas on what is causing problem? It is worry if she breaks down at night with her two little kids on board. John

 

Had a similar issue, albeit not on an Impreza.

Turned out to be the fuel pump