Just found this forum its pretty good. I think I will stick around. Anyway onto my question. I just got a 89 pickup 2WD with a 22RE and manual trans from my friend. When I got it there were multiple codes and I have fixed all of them except for one Code 27 Rear O2 sensor. I was told it had new O2 sensors when I got it and by the looks of them they are fairly fresh. The rear O2 was hardlined in and according to my wiring schematics it was wrong. I wired it what should be correctly and I'm still getting the code.

Here's how it was wired when I got it. Sensor wires listed first, harness wires second:
Blue - Black shielded white wire
White - Brown
Black - White/Red stripe
Black - Red/Green stripe

Here is how the engineer in me feels it should be wired:
Black - Brown
Black - White/Red stripe
White - Black shielded white wire
Blue - Red/Green stripe

On the sensor I know both black wires are too the heater, blue is signal, white is ground.

Did I screw up and the blue signal should go to the white double shielded wire or does anyone think the new sensor could be fried from being hooked up wrong? I checked the heater circuit on the sensor and it ohm's out good.

 

If anyone looks at this I was typing this incorrectly. I got it wired the second way. I just went and wired it as follows:
Black - red/green
Black - White/Red
White - Brown
Blue - Black shielded white

This is the correct way. Sorry for my terrible initial post. It was late and I was tired

 

The problem with these Trucks is one never knows what might have been done .

People do all sorts of wiring improvements that make no sense at times

 

I agree. I'm just a bit embarrassed about my first post. That will teach me to post while tired. Got it all fixed now and repaired all 7 codes I got the truck with. This weekend I will take it for a test drive.