I just bought a VAFC II and frog harness. I was wondering if there was and way to run an air/fuel ratio guage by running the wiresof the gauge into the harness i am using to hook up the VAFC II, instead of the sensor under the car?
Any help is greatly appreciated.
Thanks

 

I have my A/F hooked up to the map sensor wire.

IMO, it bounces around way to much. Since the guage is, mostly, useless anyway, I'm going to disconnect it from the map and run a wire down to the O2 sensor. I'm hoping the signal from it will make for a smoother sweep for the guage.

 

Yes, you can. You just have to find the equivalent to the Primary O2 sensor signal wire and splice in your A/F gauge pick up wire to this. Of course, this will only give you a "narrow band" signal, but even a narrow band readout, if used correctly, will give you some idea of how your engine is doing. It won't be good enough for tuning purposes, but it will still be useful as an "observation" tool.

I don't think the MAP sensor signal is the right type of signal for an A/F gauge. You need a Primary O2 sensor signal in order for your gauge to tell you anything remotely useful. This would be the WHITE wire that is on PIN #16 on the 31P connector at the ECU.

 

thanks xviper. You have helped me out so many times i cant even start to tell you how much i appreciate your help.
Thanks

 

That's the wire I have it hooked up to. I mis-read and thought that was the map sensor.

I was going to move the wire down to the actual O2 sensor, I'm guessing then that the signal I have is the one I was thinking of moving it to.

 

pulse- so you had the wire ran to the pin x-viper was talking about on the ecu??? Is that what you mean, or are you talking about something else???

 

If you have the correct wire, it doesn't make any difference whether you take it at the ECU or at the primary O2 sensor in the header. You are using a narrow band signal for a narrow band gauge. It is what it is. It won't get any better. You just have to understand how to read it and how to make sense of what you see.

 

how can you read a narrow band correctly so it won't be useless (don't take it wrong), I would really like to know, I could use that....Thanks a lot....



D.

 

IMHO only trust narrow band O2 sensor reading at idle. Use wideband for tuning or checking tune at rpm.

 

Like I said before, a narrow band is not for tuning, only for an indication of how the engine is doing at the critical times. Those critical times is during WOT, under boost and in the upper rev band. During these times, the narrowband readout will stabilize just enough for you to read if it's rich, lean or stoich. For this purpose, you don't need to know what the number is, just that it's in the rich to be safe. I used one for a year before getting a wide band AEM UEGO. The UEGO confirmed everything I suspected when using the narrow band.

ps. You can't really use nor do you need to know what the A/F is at idle. There is no load, no boost, no WOT. In such conditions, who really cares? It doesn't really mean anything. Also, at idle, a narrow band will also jump up and down like a yoyo, particularly when the airpump is operating.