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I've been working through the process of trying to find the source of really high HCs at idle on my 84 spider. My O2 sensor seems to check out in terms of voltage, but I'm not sure of its age, so I'm replacing it with a 3 wire sensor. 2 questions:

1. I know I've read it on here somewhere, but I now can't find the info. Any recommendations on where to tap into for the 2 o2 sensor heater wires?
2. When I unplugged the o2 sensor connection up near the brake booster, the insulation in the plug of the green wire fell apart. It still connects fine, but is that a problem (to not have the insulation around the plug)? If so, is it repairable with something?

Thanks again for all the help! You all are the best!

Ty
 

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I'd have to ponder a bit to say where to tap in for power. Basically you want a 12V+ source that is switched on/off with the ignition switch.

As for the deteriorated insulation, I'd suggest some heat shrink tube. Two layers will give more protection. For strain relief I make the first layer longer.
 

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But Mad North-Northwest
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Well, you shouldn't really need a three wire, but it won't hurt I guess. You need a 12V switched & fused power source. On the later cars it pulls from the L-jet fuel pump relay. This has an 8A fuse which is apparently sufficient for the two fuel pumps, O2 heater, and AAV heater.

If the sensor wire grounds the car won't run right. As Eric said heat shrink will work, or you can just use some electrical tape and a small wire tie to hold it in place.
 

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What year is your Spider? I did this on my '85 to help during startups and at idle because the 4 into 2 headers prevent the single wire O2 sensor from getting the exhaust heat required to work.

In the '85 there's the 02 milage warning light gizmo not for from the green 02 sensor wire. I unplugged this useless warning light gizmo and used the connection to power/ground the O2 sensor. Seems to be working very well, only have a few hundred miles since but zero issues. I also removed the bulb in the dash.
 
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