3 & 4-wire O2 sensor question

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Jul 26, 2009 | 11:50 PM

89IROCZ28

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iTrader: (14)

Joined: Mar 2000

Posts: 254

Likes: 2

From: Painesville, Ohio USA

Car: 1989 IROC Z28

Engine: 305 TBI (L03)

Transmission: 700R4 w/ Corvette servo

Axle/Gears: 4th Gen, 3.23, posi, PBR

3 & 4-wire O2 sensor question

Does anyone know if a 3 or 4 wire oxygen sensor heater circuit can be powered off after the engine warms up or does it need to stay powered to maintain closed-loop mode whenever the engine is running?

Thanks

Jul 27, 2009 | 04:45 PM

thomas1976

Supreme Member

Joined: Jun 2006

Posts: 2,199

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From: West-Central

Car: 91 Trans am

Engine: built 360 TBI

Transmission: built 700r4

Axle/Gears: 10bolt/3.23

Re: 3 & 4-wire O2 sensor question

I have the 3 wire o2 powered key on.

Jul 28, 2009 | 01:56 AM

ownor

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Joined: Sep 2006

Posts: 952

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From: Austria

Car: 84 TA / 89 Formula

Engine: LS1 / L03

Transmission: T56 / 700R4

Axle/Gears: 3.73 / 3.27

Re: 3 & 4-wire O2 sensor question

well, if i remember correctly the heater element inside the o2 sensor will only switch on during a specific temperature range (0-600°F or something?), so that's on startup till warmed up or during normal operation when some condition causes the o2 sensor to cool under its optimal operating temperature