Its not going to work
The ECU in a DSM couldnt give a shit what your coolant temps are as far as the mixture goes, except to turn the "choke" on and off. No variability. Now, this will work if you put it on the baro pressure signal line, but let me advise against it. Its a big time hack mod. Works fine on some cars, but on a turbo DSM its not worth the chance, and there are better options out there.
If you do go against my advice and try this, please, for the love of God, dont use an O2 sensor voltage guage ("blinky guage" or otherwise). Datalog the damn car. Its very easy to induce knock with a SLIGHT change in baro pressure. The AF guages will not show you this. I could go on for hours why the voltage of the stock O2 sensor is damn near completely useless on DSMs, but I'll spare everyone. Maybe another novel for another day. So be safe, use a logger.