Function of TBI o2 sensor.

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Vbb199

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So, i was discussing with a friend about fueling and ignition on the tbi trucks last night. I feel like i personally have a good overall understanding of these old antequated fuel systems i love them, theyre a niche that nobody ***** with, because they "cant make power" or are "too complicated" whatever.

Ive proven both to be wrong.


My question= whats the o2's function? I know it doesnt have dominate control over fueling like the next gen of of vortec motors do. Its a 1 wire system, not heated 3 wire.
That said, im to assume its function is probably just an exhaust temperature sensor, am i correct?

Was wondering becsuse im about 99% positive thats the original one. If it has any sort of say over fueling, id like to know, because if i can, i will test it with a torch and see if it works like it should.

Thanks pplz
 
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1985c20

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I’m pretty sure it does effect fueling. You’re correct it’s an antiquated 1 wire system. No heater, so it’s gotta be right there in the manifold to heat up. No ground it uses the exhaust manifold for that. But it’s what they had in 87. As far as I’ve always known it functions just like o2 sensors of today, albeit probably not as well.
 

Vbb199

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I’m pretty sure it does effect fueling. You’re correct it’s an antiquated 1 wire system. No heater, so it’s gotta be right there in the manifold to heat up. No ground it uses the exhaust manifold for that. But it’s what they had in 87. As far as I’ve always known it functions just like o2 sensors of today, albeit probably not as well.


Excellent. Thank you. I'll pull it sometime and check it.
 

Ricko1966

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It does tell the ecm to richen up or lean out in closed loop. Yes you can test it with a propane torch, first I'd just disconnect it put DVOM on it watch for my meter to stabilize now create a vacuum leak(lean condition) meter reading should drop. Now spray some carb cleaner in front of the intake snorkel( rich condition) meter should climb. If in doubt pull it and heat it with a propane torch with a meter attached. FWIW you can put a 3 wire in where a 1 wire came out you just have to run 2 wires for the o2 heater circuit.The advantage is O2 sensor becomes active sooner.
 
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Rusty Nail

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Measures the amount of oxygen in the exhaust gas and changes fuel trim five times per second in an effort to reduce harmful tailpipe emissions.

A one wire sensor has an effective lifespan of about 30,000 miles or ten oil changes says the guy selling the sensors. 50-60k is what the guys changing the part says.

In my experience BOSCH brand is the best choice to replace with.
 

Vbb199

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Thanks guys, if im not mistaken, that is literslly the last sensor to replace on the truck. I ordered a bosch o2
 

Chevyguy

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Measures the amount of oxygen in the exhaust gas and changes fuel trim five times per second in an effort to reduce harmful tailpipe emissions.

A one wire sensor has an effective lifespan of about 30,000 miles or ten oil changes says the guy selling the sensors. 50-60k is what the guys changing the part says.

In my experience BOSCH brand is the best choice to replace with.
Bosch makes the OE oxygen sensor for our trucks. I just replaced mine because it was reading really slow on my scanner.

Sent from my SM-A705U using Tapatalk
 

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