I've done it, and made it work
Sadly, there were just no room to add a wideband in there, there is a big AWD Tranny in the way that the sonic don't have ;-) and a big rad on the other side...
So I went with a 14point7 Spartan 3, but the narrowband output was too slow. Since I got the MPVI3 with the pro cable, I was able to read the Lambda value directly from the CANbus output of the 14point7 controller, so I've used the linear output to simulate my own narrowband by setting the 5V output at Lambda <= 0.99 and the 0V output at >= 1.00 Lambda (otherwise it was just too slow. Then I put a voltage divider there, a 1.2K resistor and a 270 Omhs resistor, and it worked like a charm. Oh and I had to put a 10 ohms resistor to simulate the heater.
You can see the hurdles I had to go through there :
https://14point7.discoursehosting.ne...t-p0133/103/10
This is the important part :
narrowband.JPG
And now it works, and I can tune, while still daily drive my car when not tuning
I know, there is a 0.005 lambda offset towards rich, but I figured that is was probably within the sensor tolerance ;-)
Hopes this helps someone else in the future.
Thank you