...also the O2 sensors are just there to try to maintain stoichiometric at
idle and low speed to keep the EPA happy. Any reputable EFI dealer should inform you that if and when the ECU sees O2 faults it will disregard them (or should) and default to carb mode. I've had O2 faults due to sensors out there too far for 15yrs. Once in a while I have to blip the throttle when coming to a stop. Also mine are 3 wire non heated...lay your leg against the sidepipe there and tell me it's not hot enough
Mike