Lately I've been wanting to log my AFR over rpm and other parameters. I remembered my ECU has the EGRt input, and knowing how ECUs work, I had an idea. Well obviously after looking it up, people thought about it before me. And good thing too haha.

Anyway, I have an LC-1 wideband and DB gauge. As you know the lc-1 comes with 2 outputs, ones mapped 0-1v for narrowband sim(yellow wire), and the other 0-5v for the gauge(brown).

After reading and sifting through a few different forums and some threads on this forum, I found out it has been done. But some problems arise.

Knowing I still wanted the gauge to be hooked up, I ran the yellow wire (0-1v) to the EGRt input. Soldered it and ran MMCD 1.8g.

HERES ARE THE QUESTIONS
Knowing that the yellow is a narrowband sim, I compared it to my o2 sensor voltage for shits and giggles.

I noticed they didnt really match up, anytime the o2 sensor was around .54v, .56v. The EGRt(narrowbandsim) voltage would be .23v for those numbers above. So they didnt match up, but followed eachother for the most part.

Why would it not be the same voltage?
Shoud it be the same voltage?
I graphed the narrowband sim, and it somewhat acted like the o2 sensor. But not completely, is this because its not an o2 sensor, but an actual air fuel sensor?

Do you guys have any exerience with this, any pointers? Things I'm going to run into?
I read when I remap the yellow narrowband sim wire to 0-5v through the lc-1, I have to match it to what MMCD knows as voltage to air fuel.(0v is 8:1? - 5v is 19:1?) And this is because what I want to do was intended for the PLX widebands?


I know its alot of writing but I tried to break it down as much as possible. Thank you guys for reading through it

Andrew

Anyone?