My car seems to wander out of Closed-Loop at idle, as most do. You can tell, as the diverter valve to the engine exhaust ports clicks on. Closed-loop is always the better deal.
Stock exhaust.
The existing O2 sensor [real GM item] has only 45,000 miles on it. I would never have thought of replacing it, but a buddy just junked his incredibly-high-mileage Audi, and he gave me his unused Bosch 3-wire sensor.
I have tried Bosch 1-wire, USA-made sensors with poor luck- they seem to run rich. This heated unit is from Germany.
I soldered on the right connector and screwed in the new sensor. Plugged her in. So far, nothing out of the ordinary. If tomorrow is warm, I will ground one of the heater wires. The Q is, where do I connect the other wire? An ignition-switched [+], a relay controlled by the [to-the-exhaust-ports] diverter valve, a simple connection to the alternator trigger lead, the choke heater? Should the sensor's heater remain on while the engine runs, or only if it wanders back into open-loop?
Or it doesn't matter because the heater will last and last regardless of how you do it.

As long as I don't confuse the computer with a cold engine and warm sensor.

Inquiring minds need to know.

Thank You,

Seth

 

I connected mine to the fuel pump relay. Works great and stays in closed loop.

 

Well, today was really warm. Can you say "Seventy degrees"?
Anyway, I connected one lead to the bracket that secures the accelerator cable to the engine, and ran the other lead to a switched connection in the fusebox and used a pigtail fuse holder from Rat Shack with a 7 amp fuse.
No fuel injection, so no fuel pump relay.
Guess what? The heater seemingly didn't work. It didn't occur to me to put the ohmmeter on the heater leads, so I just put the old sensor back.
WELL, THE HEATER NOW TESTS OUT AT UNDER THREE OHMS, SO IT MUST BE THE PIGTAIL FUSEHOLDER FROM RATSHACK. Their products are the lowest-grade shlit at best.
If Thursday is nice, the Bosch will go back, but this time, I will test out my wiring. As simple as it is [and I am great at complex wiring], it failed to work.
Boy, do I miss Lafayette Radio Electronics. Their quality always put Rat Shack to shame, even when Rat Shack had some pride. There is absolutely no place to get quality anything any more.
I was in a Pep Boys this evening to purchase a vacuum tee.
At the cashier, the person ahead of me was paying for a NEW alternator in a fancy box. I thought "WOW, now I have a place to get a new alternator for my car, as the existing one is 1/4 century old."
As I carefully read the box, I discovered the following discouraging words------------------Made in China.-------------------
Made in China, just like that fuse holder.

Seth

Seth

 

I bought a 4-wire universal bosch O2 sensor and a 4-wire water-proof connector. I cut the pig tail off the old sensor to keep from having to cut the connector off of the sensor positive signal harness wire. I connected the heater 12volt wire with an inline fuse to the ESC module 12v supply wire, the sensor negative signal wire to the ECM ground, and the heater ground to a chassis ground strap near the relays.