Lambda / Oxygen Sensors, educate me!
Discussion
The mythical world of Lambda Sensors.... I am but a Hobbit in this world and need a PH education!
Basically, I have a fine automobile upon which the Lambda sensor has died (or so says diagnostics anyway). Its a four wire lambda (2 white, a blue and a black). Am i right in thinking this is a 'wideband' lambda sensor, generally regarded as offering superior engine management over 'narrowband'? I am pretty sure I understand what it does, how and why (uses a hot wire or something to measure stoichiometric ratio and reports to ECU to alter fuel map accordingly).... but a PH explanation would be appreciated.
The next question is why are there so many different lambda probes?!! Surely they are all doing the same job and returning broadly the same values, no? If they are measuring the stoichiometric ratio surely there is only one way of measuring it?
Seeing as I need to replace the lambda probe (which has a main dealer price equivalent to the GDP of a small country), what stops me from using any 4 wire lambda probe as a replacement... or one of the 'universal' types off ebay or similar? Is the world of Lambda probes a lot more complicated than it looks?
Basically, I have a fine automobile upon which the Lambda sensor has died (or so says diagnostics anyway). Its a four wire lambda (2 white, a blue and a black). Am i right in thinking this is a 'wideband' lambda sensor, generally regarded as offering superior engine management over 'narrowband'? I am pretty sure I understand what it does, how and why (uses a hot wire or something to measure stoichiometric ratio and reports to ECU to alter fuel map accordingly).... but a PH explanation would be appreciated.
The next question is why are there so many different lambda probes?!! Surely they are all doing the same job and returning broadly the same values, no? If they are measuring the stoichiometric ratio surely there is only one way of measuring it?
Seeing as I need to replace the lambda probe (which has a main dealer price equivalent to the GDP of a small country), what stops me from using any 4 wire lambda probe as a replacement... or one of the 'universal' types off ebay or similar? Is the world of Lambda probes a lot more complicated than it looks?
Ok, well I have learnt something already! 4 wire = narrowband - thats a good start! So all 4 wire narrowband sensors are pretty much the same? Why such huge differences in price?
So I should be able to pick up a generic 4 wire sensor, splice that onto the existing loom connector and be good to go?
So I should be able to pick up a generic 4 wire sensor, splice that onto the existing loom connector and be good to go?
steveo3002 said:
you can use universal ones..it just wont have the custom length wire and plug on the end , the no name ebay ones dont last so good so if its a keep try and buy good brand
doesnt sound like a wideband to me ..although im not sure how you tell them apart
....and hope that the voltage for the heater circuit is correct.doesnt sound like a wideband to me ..although im not sure how you tell them apart
not all narrow band 4 wire sensores are the same...
yes they do the same job, but they vary quite a lot in terms of heater impedance, temp profiles, etc.
you really should get the right one for the car...
I have used this place before, they sell genuine NTK and the like:
http://www.lambdasensor.com/
(and no, I have nothing to do with them appart from buying a sensor or two)
yes they do the same job, but they vary quite a lot in terms of heater impedance, temp profiles, etc.
you really should get the right one for the car...
I have used this place before, they sell genuine NTK and the like:
http://www.lambdasensor.com/
(and no, I have nothing to do with them appart from buying a sensor or two)
Scuffers said:
not all narrow band 4 wire sensores are the same...
yes they do the same job, but they vary quite a lot in terms of heater impedance, temp profiles, etc.
Interesting... tell me more. How do they vary and how does one measure the variance? How do the so-called 'universal' ones get around this?yes they do the same job, but they vary quite a lot in terms of heater impedance, temp profiles, etc.
What effects would the un-matched lambda sensor have on a car?
larrylamb11 said:
Scuffers said:
not all narrow band 4 wire sensores are the same...
yes they do the same job, but they vary quite a lot in terms of heater impedance, temp profiles, etc.
Interesting... tell me more. How do they vary and how does one measure the variance? How do the so-called 'universal' ones get around this?yes they do the same job, but they vary quite a lot in terms of heater impedance, temp profiles, etc.
What effects would the un-matched lambda sensor have on a car?
assides that the bigger issue is some have heater ccts that are designed to be on all the time, others pulsed, thus their impedance is somewhat different, use a low impedance mabda on a ECU designed for high, and you can toast the heater driver cct in the ECU.
long and short of it, buy the right one.
There are also two distinct types of narrow band sensor that are not compatible. The most common type use a Zirconia sensor that produces a voltage, but there is also a Titania sensor that uses resistance change rather than voltage output.
The metal shield on the end of the sensors also varies according to where they are placed within the exhaust, which is why there is no such thing as a truly universal sensor that will perform to the same standard as an OEM part in all applications.
The metal shield on the end of the sensors also varies according to where they are placed within the exhaust, which is why there is no such thing as a truly universal sensor that will perform to the same standard as an OEM part in all applications.
This is good stuff! I am learning fast here... just as a PH education should be. I see, so they are not all the same....
I checked JustLambda - they don't do one for my conveyance.
So these clever Lambda johnies are more specific than they look - where can I do some research on these? I want to understand these better.
In the interim I have heeded the sage advice and plumped for an O.E. replacement - a gentleman cannot go without leather and wood for too long...
I checked JustLambda - they don't do one for my conveyance.
So these clever Lambda johnies are more specific than they look - where can I do some research on these? I want to understand these better.
In the interim I have heeded the sage advice and plumped for an O.E. replacement - a gentleman cannot go without leather and wood for too long...
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