Heated O2 question
Thread Starter
Race Director
Joined: May 2001
Posts: 14,165
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Heated O2 question
Sooner or later I'm going to have to convert my car to use heated O2 sensors before I can do any accurate tuning. I know basically there are several different variations. Some heated sensors are 3 wires, some are 4. Basically what does the 4th wire do? I can understand one for the signal, one is hot to the heater, the other is a ground. And the other one does what exactly?
Also what year did they introduce the heated O2 sensor on the C4? I've got a plan on wiring these nicely so I can still have plug in O2's just like the factory, I'll just be getting my power source somewhere else.
Also what year did they introduce the heated O2 sensor on the C4? I've got a plan on wiring these nicely so I can still have plug in O2's just like the factory, I'll just be getting my power source somewhere else.
Melting Slicks
Joined: Jan 2000
Posts: 3,418
Likes: 1
From: NW Chicago Suburbs
Re: Heated O2 question (Nathan Plemons)
Nathan,
Looking at my 96 FSM, it appears that there is a separate ground for the heater too. I assume it's so the PCM can monitor the load current of the heater with more precision. I would assume you could just use a three wire sensor and let the chassis be the ground return for the heated.
When you convert to heated sensors, do you let the PCM control the heater or do you just leave the heater on all the time?
Eric
Looking at my 96 FSM, it appears that there is a separate ground for the heater too. I assume it's so the PCM can monitor the load current of the heater with more precision. I would assume you could just use a three wire sensor and let the chassis be the ground return for the heated.
When you convert to heated sensors, do you let the PCM control the heater or do you just leave the heater on all the time?
Eric
Thread Starter
Race Director
Joined: May 2001
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Re: Heated O2 question (silver & red CE)
Well I was going to just leave them on all the time I guess. My computer won't have any provision for controling the heater. That's why I'm trying to dig up some more info about them before I just dive into it.
Drifting
Joined: Feb 2000
Posts: 1,994
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From: Charleston, WV
Re: Heated O2 question (Nathan Plemons)
If I remember right the heaters go OFF when the car goes into closed loop......... they are relay controlled (also working from memory here not the book) If you need me to I'll get the book out :seeya
Thread Starter
Race Director
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Re: Heated O2 question (vettmech)
Hmm, that's interesting. I might need to leave mine on all the time though because in the collector, even in closed loop they are slow to respond, they don't switch like they are supposed to.
Intermediate
Joined: Nov 2001
Posts: 44
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From: Lawton OK
Re: Heated O2 question (Nathan Plemons)
Nathan,
I've been looking at doing the same thing - - let me know how it goes. There is a Tech Article (in the Tech Tips section of the forum) on HT to install a Heated O2 sensor on Long Tube Headers.
:D
I've been looking at doing the same thing - - let me know how it goes. There is a Tech Article (in the Tech Tips section of the forum) on HT to install a Heated O2 sensor on Long Tube Headers.
:D
