im reading the helms manual- the o2 sensor is fine it seems. the o2 sensor would go off if there is fuel in the exhaust which i can smell- so it should be throwing that code. thats a result of the problem, not the problem itself. the problem is whatever is causing the system to limit revs to 2000rpm. and it cannot be in limp mode- ive reset the ecu and same thing minus the cel (it hasnt had an opportunity to trip due to it being driven only around the apartment complex)