2002 honda sir 2l engine
At my wits end. I have no idea where to look next. New a/f sensor, everything clean, no vac leaks, connections good. no loping idle.
at 3000 rpm the engine goes lean to rich and back every second. Short term idle trim goes from -10 to +25. Wtf

 

Got it figured out after tracing everysinge electrical connection to the ecu. It was the air/fuel sensor relay, just abovwe the ecu. 13$ relay. runs perfect now.