4-Wire O2 Sensor Woes

[350yj]

Hello,

I installed a 4-wire o2 sensor in hopes of more accurate readings on cold days driving in the snow and rain. I purchased a Bosch 15733 and wired it following the included install guide.

One white wire to an ignition relay (switched 12v +)
One white wire to ground

Black wire to ECM (D7)
Gray wire to ground (I have this connected to the ALDL ground)

In Tuner Pro, the O2 sensor voltage lists at 1054.6. Once the engine is above 48*, it starts to run lean (according to my Innovate LC2) and lacks power. Also, the MIL will illuminate; Tuner Pro reports error codes 44 and 45.

Connecting a multimeter to the Black and Gray wires with the engine running shows .208 volts.

Do I have bad wiring or a bad sensor? Or am I using the wrong sensor for this engine.

Note, the old one wire O2 sensor "worked". IE, it did not cause a lean condition.

--
Kris