ae92 20v running rich with engine light on???

[sxtc]

Gday everybody. I have a major issue with my 4age 20v.
it is in an ae92 and is a silvertop engine with stock ecu etc.
i was driving on the freeway and it suddenly lost power. it is running very rich and the engine light remains on at all times.
i have swapped the knock sensor and the o2 sensor and it was working for a little while ad then after about 80km's on the freewaty again, the engine light came back on and it was running rich again.
i would also like to note that the idle drops around 500 rpm.
Do you guys think it has to do with wiring or the afm?
Thanks guys.

[dumbass]

Check the code means
It's prob a fkt ecu as its bloody common that they fail these days
Pull covers off ecu and check for leaking capacitors