confusing engine diagnostic

[kingston]

so i've been troubleshooting the CEL on my 92 Legacy SS.

with just the black connector connected, i got a crank angle sensor, knock sensor, o2 sensor codes

then i did the diagnostic with both connectors hooked up, drove around the block and got crank angle sensor and 02 sensor codes so now i guess the knock sensor is fine.

i just replaced the 02 sensor. Now when i do just the black connector reading i get knock sensor, o2 sensor.

I disconnected the battery to clear the ECU then did the both connector test and have only code 51 for Neutral Switch or Inhibitor Switch malfunction.

So after that I did just the black connector again and the other codes popped up once again.

Anyone have any idea what's going on?

[kingston]

anyone?

[grippingdrifting]

The black connectors are for viewing previous codes; it will show all codes since the last reset.

For current codes, connect only the green connectors.

Connecting both sets of connectors at the same time is used for resting the ECU.

Here is where I got my info: http://www.surrealmirage.com/subaru/engine.html

[Legacy777]

Current codes will show up with the black connectors.

The green connectors are a more thorough check mode. If you get stuff to show up with just the green connectors.

Both connectors clears the codes.