Mine is also a 92 california car with a 5-wire oxygen sensor. ECU is L00. I'm also planning on the swap to a fed ECU, so let me know how yours turns out.
Well I swaped in the Fed ECU, no check engine lights. Everything seems fine. I didn't change anything but the ECU. My last two tanks of gas was 51.7 mpg and 53.2 mpg. So I'll see what the lean burn can do!