Sorry, wasn't getting notifications...
Bushwick - I think you are correct, and I just put a wideband on the car and it's very rich at idle after it warms up. 14s when it's cold, 10s after it warms up.
nipper - the only code I'm getting is for knock sensor. I have one on order arriving tomorrow. The wideband shows a huge lean spike at 5000 rpm, so I guess either it's cutting fuel because it's in limp mode, or something else is causing the lean spike and it's pulling timing due to knock.
grossgary - not 100% confident of the wiring, but no codes other than knock sensor and misfire flashing, which happens at key on engine off. Running issues existed before the knock sensor code, also.
wtdash - yes, I'm familiar with 2slo4u's car, he actually helped me a lot in getting mine running. I used the same jdm ecu and followed what he did... problem is, his swap was 7 or 8 years ago, and he doesn't remember much about the wiring issues he had.
So now that I have the wideband, I know it's a fueling problem, but cause is unknown. Symptoms are, runs nice, almost perfect when cold, when warmed up, super rich idle with misfires, cruise is OK, but AFR is all over the place between 13 and 15, acceleration gets richer, but AFR still fluctuates, more like 12 to 14, and when I nail the throttle, it spikes lean at 5000 rpm in every gear, even neutral.