Technical Gurus. Please help. i need help

[Jiayong]

Please take a look at this product.

 

http://www.obitasia.com/index.htm

 

 

Anyone can explain what it does and does it really justify its cost?

 

So far i know that stock oxygen sensor(narrow band) can detect ranges from 14.0 - 15.5? while the "bosch wideband sensor" detects ranges from 11.0 - 17.0

 

Can anyone explain how the oxygen sensor, the obit controller and the ECU work together?

[Jiayong]

UPZ...cos no one reply...

[Yeobh]

Email the company, they should be able answer all your questions.

[Limws1]

I'm not sure how Obit and ECU work together, maybe you need to find out from the maker of Obit. If you want to know how ECU and oxygen sensor work together, please read up here:

 

http://home.flash.net/~lorint/lorin/fuel/lambda.htm

[Jiayong]

Extract from the article

 

"

The factory recommends that the sensor be replaced every 30,000 miles. If the sensor has been exposed to one of its poisons, its lifetime is even shorter. Do your car a favor by replacing the poor little Lambda sensor with an official Bosch unit and have a healthier and happier car...A small sacrifice for such a big gain. "

[/color]

The Bosch unit has a range from 11 - 17. Does anyone know that if the sensor needs a controller to work properly?

 

Buying the sensor is not too ex. $79 from the local website. But its the controller that brings it close to $1K.

 

Does anyone know if it is redunlant to use just the sensor alone with out the controller? Assuming of course the car's ECU can be programmed to recognise that the sensor is a Bosch Sensor, do we still need the controller?

[Jiayong]

oops..and thanks for the article. :) it has been enriching.

[Dwoon]

Dunno how true but I understand that wide band lamda sensors to have a rather short life span as compared to our stock ones.

[Jiayong]

Really? you mean like those Bosch sensors? I would think that stock ones are long lasting...cos i have never heard of anyone with a stock setup saying that he needs to change his/her oxygen sensor...

 

 

 

But the extract that i pulled out seemed to suggest a Bosch Sensor will last longer??

 

 

Sigh, why am i in comp engine...i should have done mechanical or automotive.

 

Maybe i am destined to write ECU programs...hee hee..

[Thumbs]

Stock narrow band is only accurate around stoichiometric and so is useless for tuning anything other than idle/lean cruise, you'd need a wideband O2 sensor. Since torque and fuel efficiency are determined by air-fuel ratio to a large extent, it is important to be able to know the actual AFR which can only be determined by a proper WBO2.

 

The Obit is just a piggyback meaning to say it intercepts signals from the sensors to the ECU and fools the ECU to achieve certain results.

[Thumbs]

The wideband O2 sensor needs a controller to work properly unless the circuitry is built inside the ECU.

[Thumbs]

Stock O2 sensors can and do fail. Wideband O2 sensors need to be heated up before being exposed to exhaust stream or they will fail quickly.

[Jiayong]

Thanks for your answers. I think i have managed to grasp the concept.

 

Did know that this air/fuel ratio thingy is so important....no matter how much tricks you have in your engine bay, without proper A/F ratio, everything is a waste.

[Dwoon]

Can I plug in a wide band in replacement of my stock narrow band O2 sensor? Is this possible? Are there any trade offs?

 

Thanks.

[Thumbs]

Optimal AFR is actually a range, not a specific number. It can be proven on a dyno that variations of as much as 0.2 lambda from target AFR have no effect on torque. Spark advance, on the other hand, is a whole other matter. For a turbo car 2.5 degree of spark advance is roughly approximate to raising boost by 0.1 bar.

[Thumbs]

Since you have no control over the closed loop cycle, there is no point doing this.

 

Programmable standalone ECUs on the other hand allow you to set the target lambda over a wide range of operating conditions and adjust the fuel (and indirectly, the AFR) as appropriate, either in open loop or closed loop mode.

[Dwoon]

But functionally, can the wide band replace the stock narrow band in normal operating mode (i.e. not doing tuning). Wonder if the voltage (data) is compatible to the stock one.

 

Although I have no control on it, but will it allow my tuner to easily plug in through the ODBII port for readings whenever required? Saves me the trouble to go to a workshop to have the wide band installed whenever I need fine tuning. I was hoping it'll serve 2 purpose.... for normal use.... as well as when tuning is required.

 

Thanks.

[Thumbs]

Short answer is no because narrowband outputs 0-1V while wideband is 0-5V... besides this like I said the stock ECU doesn't make use of all that resolution a wideband provides, because it is expecting to see mixtures around stoichiometric.

[Dwoon]

OK, thanks. The differing voltage outputs is self explanatory.