Hondata

I have a PPL ECU that i bought from KPower industries with a KPro v4. When I brought the car to get tuned 2 years ago the tuner that Xenochron had do it (Michael at Syn Garage) said there was an issue with my O2 sensor readings and he just tuned it open loop. It worked and I didn't care.

Now I want to get a remote retune on the track by E-Tunez. And the O2 sensor has become an issue. So I have been looking into fixing it. I have found something strange and want your opinion.

The Denso 234-9005 O2 sensor has 4 wires
White = Relay = O2 Heater Positive
Green = ECU A1 = O2 Heater Ground
Red = ECU A6 = O2 Sensor Signal
Yellow = ECU A16 = O2 Sensor Ground
I have confirmed all of those connections

The strange part is what I get for voltage at the O2 connector when the sensor is disconnected and the ignition is on.
White = Relay = 12.2v (battery voltage)
Green = ECU A1 = 2.8v
Red = ECU A6 = 2.1v
Yellow = ECU A16 = 1.8v

Now let's add to this strangeness
Green = ECU A1 = Open to Ground
Yellow = ECU A16 = Open to Ground

This means to me that something is very messed up in this circuit. Grounds don't go to ground? Grounds have power?

Any ideas?

Have you tried the ECU on a known working vehicle?