I've read from the Hondata website sent to me by one of the users here at hondaswap http://www.hondata.com/techo2problem.html I am having the same problem as described before: ecu in the closed loop under light throttle and runs good with open loop, when under heavier throttle. From my understanding OBD0 and OBD2 both have 2 o2 sensors, and OBD1 only reads one, correct?? I am only running 1 o2 sensor with an obd2 wiring harness, obd2-1 clip and a p28 obd1. I am trying to ask: According to the article I should not be having this problem, is it because the the ECU's reading from the plug that's not plugged into the o2 sensor? If the obd1 p28 ECU gets no readings from the o2 sensor what would happen? and lastly, p28 only reads one o2 sensor correct??? thanks.