xkalib3r

They are also known as the Check connectors. Each connector only has one wire attached.

For putting the car into test mode as described by the clicking of the relays yes. I'm sure the black connectors would generate codes? Works 100% like that on my 97 legacy

Hi Try and do a self diagnostic on the car. Under the dash there should be a pair of black cables with clips. With the ignition off, plug these two in to each other. Turn only the ignition on. Check the CEL light and note the flashes. If the light flashes steadily then all should be good. If however you see the flashes changing pace then refer to a trouble code guide such as http://www.troublecodes.net/Subaru/ (1988 and later models with Multi-Point Fuel Injection (including Legacy)) A short flash represents a 1 and a long flash represents a 10. So for example 2 long flashes and 5 short flashes would equivocate to 25. Compare the numbers to the code list. A word of advise though, if you are getting error codes, let them cycle a few time before trying to record the numbers. It can be a bit tricky when there are multiple codes. It may not be an ECU problem but rather a sensor. Sounds to me like either a coolant temp sensor or Mass Airflow Meter/Sensor. Hope this helps!