Wideband 02 sensor purpose?

[wbradley]

Hi, I have a question that people might know the answer or have a knowledgeable opinion -

When my car was dyno tuned last year the tuner commented I ought to get a bung welded in the over pipe and install a wideband sensor. He also told me the tune was speed density based and the MAP meters the air so temperature and things can affect the engine control.

So, is the wideband sensor added to the Ecutek parameters for the ECU or is this just for me to monitor or set failsafe for lean/rich condition?

[Amputechture]

They detect a wider range of oxygen to fuel. From what I understand, the factory O2 sensors do not read accurately once the exhaust gets to a certain point on the rich side because the sensors were never meant to see it in that window. Although the factory O2 sensors can be rescaled to read within the same range and a lot of tuners claim that widebands are more of a hassle than anything because of this.

[GsxrMe]

I use aem failsafe that monitors my a/f and boost/vacuum and its set to kill my ignition after being 10.9/1 for more than afew secs and if boost hits more than 10psi for a few secs. ECU doesn't have a clue its there and its not part of my tune.

The gauge is awesome and can be a life saver, i just had to use it when my fuel pump just started to take a shit.

[Toyota John]

You have two options
1) install a wideband to view your AFR
2) install a wideband to an unused input and with custom maps in ECUTEK can log it for easier tuning.

[wbradley]

Originally Posted by Toyota John

You have two options
1) install a wideband to view your AFR
2) install a wideband to an unused input and with custom maps in ECUTEK can log it for easier tuning.

So then the wideband would have made the vehicle easier to tune had there been one installed prior to tuning?
Really what concerns me is whether it is necessary to optimize the engine control. So, I gather it is not tied to ECU parameters then?

Sorry if I seem kind of dense on the subject. If it doesn't affect performance I am not too concerned. Overboost not a concern, my pulley limits that. Never heard engine knock ever.

[Kodename47]

Originally Posted by Toyota John

You have two options
1) install a wideband to view your AFR
2) install a wideband to an unused input and with custom maps in ECUTEK can log it for easier tuning.

3) Both of the above

[steve99]

Originally Posted by Toyota John

You have two options
1) install a wideband to view your AFR
2) install a wideband to an unused input and with custom maps in ECUTEK can log it for easier tuning.

Originally Posted by Kodename47

3) Both of the above

theoeticly you could rescale the stock 02 sensor to read down to 10 afr


then create a custom map in ecutek of afr vs boost and trigger a failsafe if boost vs afr is outside desired limits all within ecutek software, no hardware required. ?

[wbradley]

steve99 , I consider you authoritative on the subject.

I am wondering if the quality of my custom dyno tune is what it should/could have been or since I didn't have a wide band does that mean I end up with a half-assed tune? I am wondering if he would have used AFR parameters read from the wide band otherwise and if that in fact would result in a better tune. NO CL's, etc.

Right now with speed density tables applied I understand that means the air is metered by the MAP rather than the MAF, and adjusted for intake temperature? If that is correct then temp will correct for air density, but a wide band actually has real time feedback from the resultant exhaust.

I am just wondering if I am settling for a half-ass tuning job the way I am set up now.

I just want someone to say yes you really do need this or no it is not necessary except for an over boost or lean/rich alarm.

[Kodename47]

Originally Posted by wbradley

I am wondering if the quality of my custom dyno tune is what it should/could have been or since I didn't have a wide band does that mean I end up with a half-assed tune? I am wondering if he would have used AFR parameters read from the wide band otherwise and if that in fact would result in a better tune. NO CL's, etc.

Right now with speed density tables applied I understand that means the air is metered by the MAP rather than the MAF, and adjusted for intake temperature? If that is correct then temp will correct for air density, but a wide band actually has real time feedback from the resultant exhaust.

I am just wondering if I am settling for a half-ass tuning job the way I am set up now.

I just want someone to say yes you really do need this or no it is not necessary except for an over boost or lean/rich alarm.

Most dynos have a WBO2 that would have been put in the tailpipe. I would expect that they will have tuned off this, not logged AFRs. A WBO2 in the exhaust is not necessary at all for an SC car that is tuned correctly. Unless you're going to spend time tuning from a WBO2 on the road then you'll gain little by installing one.

[nickw14]

Delicious apparently scales the stock O2 sensors to read more accurately/wider range. Zach told me I didn't need a wideband. ... after I already bought one.

[steve86gt]

Im running an AEM failsafe afr , best investment !!

[Toyota John]

ECUTEK has a suggested O2 scalling for the lower AFR numbers. You need to change the resolution as well as AFR numbers lower then 14.7 don't have much use to the ECU and there are less points down there. I have been using them but the scale is not accurate below 12. I have been rescaling the points below 14.7 to be more accurate. I am willing to bet that this will need to be done on each car as the sensors might not be the same on every car.