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Location:
Adelaide
Registered:
September 2004
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Oxygen sensor placement
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Fri, 22 July 2005 13:59
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I have heard that it is best to place the O2 sensor within half a metre of the head, but I have also heard one of the reasons the VN Commodore runs crap is because the sensor only reads one bank of cylinders.
Most cars i've seen have the sensor placed to only read one or two cylinders. I'd like to put it at the end of my 4-2-1 extractors to read the gas from all cylinders, but this is a fair way back. What effect does distance have? Surely the only change in the gas with distance is the temp and density, nothing chemical...? Is there an ideal position for the sensor?
What do people think? All opinions/comments/help appreciated!
Thanks
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Oxygen sensor placement
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Fri, 22 July 2005 14:33
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my opinion (suuuree. you wanted it  )
unheated sensor, within 1-2 feet from the head for NA or from turbo on .. turbo cars..
heated sensor can be wherever.. my heated one was at the end of the gearbox and was always fast to respond..
all cylinders is useful, but only if things go wrong.. during normal running there should be not much difference between cyl's so ideally it could sample off one..
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Oxygen sensor placement
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Fri, 22 July 2005 14:35
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| LeZZa wrote on Fri, 22 July 2005 23:59 |
but I have also heard one of the reasons the VN Commodore runs crap is because the sensor only reads one bank of cylinders.
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no no, it's because they use a Buick V6 motor that they run crap 
O2 sensor is for cruise only.
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Location:
Perth
Registered:
May 2005
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Re: Oxygen sensor placement
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Fri, 22 July 2005 14:40
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my g/f has a Lexcen (VN 3.8 V6)an she had one die in hers put it as close as you can to the location of where it was originally as It could effect fuel ecconomy & fuel/air ratio readings if the computer is getting a slightly different info.
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Location:
Adelaide
Registered:
September 2004
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Re: Oxygen sensor placement
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Sun, 24 July 2005 16:41
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So how to do you tell if your sensor is heated or not? The engine i'm about to get the exhaust done for is a 4agze.
What is the theory behind having a heated sensor?
| oldcorollas wrote on Sat, 23 July 2005 00:05O2 |
sensor is for cruise only.
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So the O2 sensor doesn't work all the time to fine tune the amount of petrol injected...?
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Location:
Sydney
Registered:
February 2003
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Re: Oxygen sensor placement
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Sun, 24 July 2005 18:18
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i believe a heated sensor has several wires (three or four i think) coming off it, where as non heated will only have one
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Oxygen sensor placement
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Sun, 24 July 2005 20:16
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| LeZZa wrote on Mon, 25 July 2005 02:41 |
So how to do you tell if your sensor is heated or not? The engine i'm about to get the exhaust done for is a 4agze.
What is the theory behind having a heated sensor?
| oldcorollas wrote on Sat, 23 July 2005 00:05O2 |
sensor is for cruise only.
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So the O2 sensor doesn't work all the time to fine tune the amount of petrol injected...?
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yup, 3 or 4 wires is heated.
theory is it has a heater so it stays hot, rather than ONLY being heated by the exahust gas (they need to be hot to be accurate, or to work at all...)
at cruise/idle, if the sensor is too far away it will get too cold.
nope, it will only (usually) affect mixtures when rpm is above a min, throttle is below a max, and absolute MAP is also below a max (ie when not loaded too much).
nonheated can have two wires also.. the second being the sensor ground wire, as opposed to grounding thru the exhaust pipe..
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Location:
Melbourne
Registered:
May 2002
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Re: Oxygen sensor placement
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Mon, 25 July 2005 03:30
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The sensor needs to be hot otherwise the zirconium or watever the element that is in the 02 sensor will only react with oxygen and produce a stable voltage that the ecu can read and referece a mixture. They are heated so your car can start to run close loop and utilise emision control systems much quicker rather than waiting for the sensor to be heated by exhaust gases.
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Location:
Adelaide
Registered:
September 2004
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Re: Oxygen sensor placement
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Mon, 25 July 2005 12:08
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Sweet, thanks for the help everyone!
I guess mine's heated, so when i get the exhaust made i'll have it at a point where it can read all cylinders.
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