NGK AFX install: why does it say 12v power should use switch/relay?

[eclipsegsx1736]

Have you wired the sensor to log in DSMlink? If and when you do, let me know how it works. I tapped into the Baro input (since i have a MAFT and it isn't needed) and I noticed that when the AFX displays 16.0, DSMlink says 15.8 and when the AFX says 10.0 the DSMlink says about 9.9. I'll post on the dsmlink forums and see what htey say but figured I'd ask you.

 

[Rice Over Wheat]

Yeah I get similar behavior. I'm tapped into rear O2 pin 75. I'm guessing this is because narrowband is between 0 to 5 volts and it extrapolates against the 9.0 to 16.0 wideband scale that the AFX can read. So 0 = 9 and 5 = 16. And since dsmlink takes this and converts to wideband a/f ratio, maybe that's why they never are exactly the same?

That or maybe NGK really means it when they suggest a 45 minute free air calibration. I did a 10 min one as I am impatient and 3 min is the minimum.

 

[eclipsegsx1736]

Haha, me too. Had to get to work. I barely did it for 5 minutes. I'm considering turning the calibration knob to see if I can cheat it a little that way. Although, now that I think about it, I don't think it's due to calibration. When you're off the gas, the A/F ratio is way beyond 16:1 and the AFX will put out 5.0v, but even then DSMlink only displays 15.8.

 

[Rice Over Wheat]

Weird, actually I've seen as lean as 18:1 at idle in dsmlink with AFX showing it's ceiling of 16. Oh well I guess it's both science and an art when it comes to tuning with wideband.