So in my hope to gain in the MPG department I replaced the o2 sensors (original and just about to turn 100Kmiles).
I purchases an aftermarket set with claimed matching plugs for a "direct fit."
Negatory on that.
The sensors were an exact match to the harness side (male) and so I had to splice the old sensors plugs onto the new sensors.
At the same time, while removing one of the old sensors, the wires pulled out (literally fell out) of its plug.
I researched the wiring diagram and came up with this:
LH pre-cat sensor:
(Harness-to-sensor respectively)
Orange->Black
Red/Black->Grey
White/Orange->White
Brown/Pink->White

RH pre-cat sensor:
Blue->Black
Red/Black->Grey
White/Orange->White
Brown/Pink->White

Installed with crimp & heat-shrink/seal butt connectors.

2 drive cycles and CEL/MIL on. P0135 & P0155
OBD II P0135 Oxygen Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)
OBD II P0155 Oxygen Sensor Heater Circuit Malfunction (Bank 2, Sensor 1)

Cleared and they returned directly after 2 cycles.
I'd be doubtful the new sensors are both defective so I'm leaning towards the wiring of the heater circuits. I see on the Service Manual that they link all the Brown/Pink leads together.
Possibly I got the whites mixed up but I didn't see any number designations on the sensor plugs to determine positions 3&4??

Help?

 

I have double checked your wiring and it all looks correct. I would tend to agree with you that you got the 2 white wires crossed. Did your new sensors come with a piece of paper that labels which wires were for each function?

Did you check fuse #2 under the hood?

O2 color wire guide.pdf
O2 pin information.pdf

 

double check your wiring, but some emission item require a certain amount of cycles before they will clear.
i don't remember if 02 are one of them, that is to keep you from clearing them while waiting in line for inspection.

 

Just found this in our Snap-On Vantage-Pro:
Harness side picture for wire designation: (I'll verify the wires are in the correct orientation, but it's hard to tell the difference between one white wire and the other white wire coming from the sensor).