Did you confirm that the circuit was open? For which wire, 71 or 3?

 

Well if it isn't the lavender -red tracer wire for heater control, then must it be the ground wire for that circuit?

For ecu wire 3, the o2 heater control 4 vc.I jumped that to the ecu to no avail----4 on the valve cover goes to 3 on the ecu--

I tried to meter the resistane on the wires at the valve cover and couldn't pull a constant reading seemed to flicker between open and 16 ohms. --1 &3--

I'd chock it up to bad gound if that made sense.

I had 12v @ vc pin 1

 

There's no fuses for the heater circuit is there?

 

Not that I recall. What 02 sensor did you buy to replace the stock one? Do you have an part details to make sure its the correct one?

When you jumpered that circuit in your test did you remove the pin from the valve cover side of the plug? Sorry, if this is a dumb question, but if that wire has a break in it, like mine did then you will get inconsistent values, like I did. To confirm you have to push the pin out of the plug, if you don't want to cut the wire, and rig up a test to the rear of the other side of the receiving plug. (solder the tip and press it into the other side)

 

The sensor I used is here and is the oem Denso found on amazon.

I jumped the wire directly to the wire. I cut the plug off

 

I can't quite visualize that. If you cut the plug completely off did you test for throughput on the 71 and 3 wire so that we know those wires are not broken, open circuit?

 

Ok I haven't redone the pin 3 test as I had mistaken the 3 pin for 5 the green wire ... At the ecu. Will recheck that. O2 sensor still works just getting heater code as always