EGO values not matching: MS3 vs MTX-L

[rth]

How do I correct the MS3 to show the values I'm seeing on my dashboard MTX-L for wideband lambda?
The difference is usually about 2 or so, with the MTX-L reading a higher number.

Thanks in advance.

[rth]

The MTX-L uses a Bosch Wideband O2 Sensor (LSU4.2).

Going to http://www.megamanual.com/mt28.htm#oa tells me to go to
Tools > Unlock calibrations
then
Tools > Calibrate AFR Table
then
Select an EGO Sensor from the drop down menu.

The Bosch LSU4.2 isn't an option. I selected Innovate LC-1/LC-2, which gets the values within 0.5 of each other but still isn't quite right.

What is the best choice for the Bosch LSU4.2?

Thanks!

[hardline]

The problem is just a ground offset. I fixed my problem by running it through a TinyIOx and connecting to the MTX-L through serial data.

[rth]

Yes, it's an offset or slight mismatch in values.

http://www.innovatemotorsports.com/supp ... %201.2.pdf

Innovate's MTX-L has a few ways to fix this: Using the serial connection to the MTX gauge itself you can program whatever values you want to see in the analog line output. Or you can look up the table in the link above which is 0v for AFR of 7.35 and 5v for an AFR of 22.39 (gasoline) and enter these values into the custom menu option.

On my motor there is still an offset, which I correct by tweaking the values of the table a bit on the MS3.

[noname4me]

Yes, it's an offset or slight mismatch in values.

http://www.innovatemotorsports.com/supp ... %201.2.pdf

Innovate's MTX-L has a few ways to fix this: Using the serial connection to the MTX gauge itself you can program whatever values you want to see in the analog line output. Or you can look up the table in the link above which is 0v for AFR of 7.35 and 5v for an AFR of 22.39 (gasoline) and enter these values into the custom menu option.

On my motor there is still an offset, which I correct by tweaking the values of the table a bit on the MS3.

I have a MS3X and MTX-L WBO in my 97 Miata with NB2 1.8L VVT engine and have had this same offset issue in readings between the gauge and the MS3. After trying different setups/configs in both the MTX-L and the MS3 WBO calibration, I found that setting the MTX-L to output 0-5v/10-20AFR and then in the MS3 WBO calibration using 0.15-5v/10-20AFR (note that the 0.15volt starting offset) results in the gauge and TS matching within 0.1AFR of each other.

One day I am going to try moving the MTX-L ground over to the MS3, but since the MTX-L only has one ground for the sensor heater and the gauge, I am not sure if that is the best approach. Using a TinyIOx and reading the serial data stream would be ideal though and is on my longer range "to do" list.