S6GP with LSU 4.9 linearisation help, please

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Joined: Mon Jul 26, 2021 7:25 am

S6GP with LSU 4.9 linearisation help, please

Post by alackofspeed »


I am trying to get a Bosch LSU 4.9 lambda sensor working on an S6GP. The sensor has been wired as the instructions:

https://drive.google.com/file/d/1ZJgG6a ... sp=sharing

Lambda 1 linearisation was set as below (Syvecs db), however, this resulted in a totally incorrect lambda reading - checked with an Innovate LC-2 - with the lambda showing lean when rich and vice versa.

https://drive.google.com/file/d/1c9wiCj ... sp=sharing

A friend has an LSU 4.2 on his car - also fitted with an S6GP - and curiously his lambda linearisation is as below:

https://drive.google.com/file/d/1EEIG4k ... sp=sharing

Having learnt the above about my friend’s lambda linearisation, I made a conversion linearisation from the Syvecs database 4.2 to 4.9, and produced the below:

https://drive.google.com/file/d/1tzqiGM ... sp=sharing

From static testing in the garage, the above linearisation appears to be okay around stoichiometric mix, however, I am presently unable to test when driving - car isn’t road legal.
What I’d love to understand, is why the stock database LSU 4.9 file doesn’t work on this particular S6GP and LSU 4.9. The wiring has been checked and it is definitely as the Syvecs instructions, the sensor appears to be working fine, but there remain questions about the linearisation.

I’d really appreciate some help on this, as I have concerns about the lambda being incorrectly reported by the ECU with my linearisation.

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