hi all i have a 1994 impreza type ra.
when i was driving home on the motorway my engine light came on!!!
but when i stopped in traffic it went off then when got got back up to speed it came back on and so on!!!
what could this be ive had the knock sensor changed the idle spped control valve set up and now im stuck with what to do!!
when i connect the black connecters together it brings nothing up??
any ideas please or help
thanks alot rich

 

It may be detting at top end. Put it on a dyno to see if all is well.